What's Wrong with Industrial Agriculture

Environmental Health Perspectives Volume 110, Number 5, May 2002
How Sustainable Agriculture Can Address the Environmental and Human Health
Harms of Industrial Agriculture

Leo Horrigan, Robert S. Lawrence, and Polly Walker

Center for a Livable Future, Johns Hopkins Bloomberg School of Public
Health, Baltimore, Maryland, USA

* Introduction
* Impact of Food Production on the Environment
* Impact of Food Production and Diet on Health
* Pesticides and Health
* Industrial Food System and Public Health
* Sustainable Agriculture
* Conclusion


The industrial agriculture system consumes fossil fuel, water, and topsoil
at unsustainable rates. It contributes to numerous forms of environmental
degradation, including air and water pollution, soil depletion, diminishing
biodiversity, and fish die-offs. Meat production contributes
disproportionately to these problems, in part because feeding grain to
livestock to produce meat--instead of feeding it directly to
humans--involves a large energy loss, making animal agriculture more
resource intensive than other forms of food production. The proliferation of
factory-style animal agriculture creates environmental and public health
concerns, including pollution from the high concentration of animal wastes
and the extensive use of antibiotics, which may compromise their
effectiveness in medical use. At the consumption end, animal fat is
implicated in many of the chronic degenerative diseases that afflict
industrial and newly industrializing societies, particularly cardiovascular
disease and some cancers. In terms of human health, both affluent and poor
countries could benefit from policies that more equitably distribute
high-protein foods. The pesticides used heavily in industrial agriculture
are associated with elevated cancer risks for workers and consumers and are
coming under greater scrutiny for their links to endocrine disruption and
reproductive dysfunction. In this article we outline the environmental and
human health problems associated with current food production practices and
discuss how these systems could be made more sustainable. Key words: diet,
environment, health, industrial agriculture, sustainability, sustainable
agriculture. Environ Health Perspect 110:445-456 (2002). [Online 20 March


Address correspondence to L. Horrigan, Center for a Livable Future, Johns
Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Room
8503, Baltimore, MD 21205 USA. Telephone: (410) 502-7575. Fax: (410)
502-7579. E-mail: lhorriga@jhsph.edu

We appreciate the helpful suggestions made by reviewers J.J. Boland, B.
Halweil, D.R. Keeney, and M. Taylor. C. Davis provided invaluable research
assistance, and M. Frazier helped produce the graphics. H. Lerner provided a
generous grant to support research for this article.

Received 20 February 2001; accepted 26 September 2001.

The Union of Concerned Scientists (1) said that industrial agriculture
views the farm as a factory with "inputs" (such as pesticides, feed,
fertilizer, and fuel) and "outputs" (corn, chickens, and so forth). The goal
is to increase yield (such as bushels per acre) and decrease costs of
production, usually by exploiting economies of scale.

Industrial agriculture depends on expensive inputs from off the farm (e.g.,
pesticides and fertilizer), many of which generate wastes that harm the
environment; it uses large quantities of nonrenewable fossil fuels; and it
tends toward concentration of production, driving out small producers and
undermining rural communities. The following environmental and public health
concerns are associated with the prevailing production methods:

* Monocultures are eroding biodiversity among both plants and animals.
* Synthetic chemical pesticides and fertilizers are polluting soil,
water, and air, harming both the environment and human health.
* Soil is eroding much faster than it can be replenished--taking with it
the land's fertility and nutrients that nourish both plants and those who
eat them.
* Water is consumed at unsustainable rates in many agricultural areas.

Many of the problems inherent in industrial agriculture are more acute when
the output is meat. Our food supply becomes more resource intensive when we
eat grain-fed animals instead of eating the grain directly, because a
significant amount of energy is lost as livestock convert the grain they eat
into meat. Cattle are the most inefficient in their energy conversion,
requiring 7 kg of grain to produce 1 kg of beef (compared to 4:1 for pork
and 2:1 for chicken) (2).

Despite this inefficiency, livestock diets have become higher in grains and
lower in grasses. The grain raised to supply feedlots (cattle) and factory
farms (chickens, hogs, veal calves) is grown in intensive monocultures that
stretch over thousands of acres, leading to more chemical use and
exacerbating attendant problems (e.g., pesticide resistance in insects, and
pollution of surface waters and aquifers by herbicides and insecticides).

The use of growth-promoting antibiotics in animal agriculture is thought to
be one of the factors driving the increase in antibiotic resistance in
humans. In addition, the most prevalent foodborne pathogens are
overwhelmingly associated with animal products, most of which come from
factory farms and high-speed processing facilities. The crowded conditions
in factory farms, as well as many of their production practices, raise
ethical concerns about the inhumane treatment of animals.

Because they contain excessive amounts of fat--particularly saturated
fat--and protein, animal-based diets are linked to many of the chronic
degenerative diseases that are characteristic of affluent societies, such as
heart disease; colon, breast, and prostate cancer; and type II diabetes. The
animal-based diet that prevails in the industrialized world--and is on the
rise in many developing countries--thus harms both the environment and the
public's health.

High consumption of animal products in affluent countries can be placed in
the context of broader global inequities between industrialized and
developing countries. Since 1950, meat consumption has doubled among the
world's richest 20%, whereas the world's poorest quintile has not increased
its consumption of meat much at all (3).

Some portions of the developing world are beginning to adopt Western dietary
patterns and, as a result, are experiencing an increase in the chronic
diseases associated with a richer diet. China offers a sobering case in
point: meat consumption nearly doubled countrywide during the 1990s (4),
with the increase especially pronounced among urban residents. This dietary
shift is considered a major reason that chronic diseases have become a more
common cause of death in China, with acute diseases becoming less common
because of improvements in water, sanitation, and immunizations. According
to Zhao et al. (5), measles, tuberculosis, and senility were the three most
common causes of death before 1950, but in 1985 malignant tumors,
cerebrovascular disease, and ischemic heart disease were the most common. To
support its "Westernizing" diet, China has also begun a shift toward more of
the resource-intensive agricultural practices that predominate in richer

Resource-intensive agricultural practices are considered unsustainable for
two reasons: much of the consumption is of nonrenewable resources, in
particular, fossil fuels; and consumption of some renewable resources is
occurring faster than the rate of regeneration.

Developing a sustainable economy involves more than just a sustainable food
system, and the food system involves more than just agriculture. However,
because agriculture can have such profound effects on the environment, human
health, and the social order, it is a critical part of any movement toward

Sustainable agriculture systems are based on relatively small, profitable
farms that use fewer off-farm inputs, integrate animal and plant production
where appropriate, maintain a higher biotic diversity, emphasize
technologies that are appropriate to the scale of production, and make the
transition to renewable forms of energy. The average U.S. farm uses 3 kcal
of fossil energy in producing 1 kcal of food energy (in feedlot beef
production, this ratio is 35:1), and this does not include the energy used
to process and transport the food. Sustainable systems involve less reliance
on chemical inputs and decreased emphasis on economic efficiencies that
shunt environmental costs onto society.

The health of both the environment and humans would be enhanced if more of
our farms made the transition to sustainable systems of production. A more
sustainable food system would involve closer connections between producer
and consumer, meaning more direct marketing of foods to local consumers
(through farmers markets, community-supported agriculture farms, farmer
cooperatives, etc.). These localized marketing strategies mean shorter
distances from the farm to the dinner plate, and therefore less energy use
for food transport.

In this paper, we use examples from around the world to illustrate our
points, but we place heavy emphasis on the U.S. food system because it
represents one of the worst-case examples of the pitfalls of industrial
agriculture. The type of agriculture that has become conventional throughout
the industrialized world is, in historical terms, a new phenomenon. Humans
have practiced agriculture for more than 10,000 years, but only in the past
50 years or so have farmers become heavily dependent on synthetic chemical
fertilizers and pesticides and fossil fuel-powered farm machinery.

In that half-century of ascendance, industrial agriculture has substantially
increased crop yields through high-yielding plant varieties, mechanization,
and synthetic chemical inputs. For example, U.S. farmers were producing 30
bushels of corn per acre in 1920, whereas 1999 yields averaged about 134
bushels per acre, an increase of almost 350% (6,7).

The higher yields of industrial agriculture have come, however, at great
cost to the environment and the social fabric--costs that are not included
in the price of our food (economists would call these costs
"externalities"). Low prices at the grocery store give us a false sense that
our food comes cheap, but they do not include the cost of cleaning up farm
pollution, for example, or the cost of vast government subsidies to
agriculture. In 1996, the U.S. government spent $68.7 billion on
agricultural subsidies, which translates into $259 per consumer and even
more per taxpayer (8).

Industrial agriculture's tendency toward larger, more mechanized farms has
also exacted a social toll. Studies have shown that farm consolidation leads
to the deterioration of rural communities (9). According to University of
California anthropologist Dean MacCannell:

We have found depressed median family incomes, high levels of poverty, low
education levels, social and economic inequality between ethnic groups,
etc., ... associated with land and capital concentration in agriculture

In this paper we first outline the environmental and public health problems
associated with our current agricultural system, highlighting animal
agriculture as a worst-case example. We then discuss how a sustainable
agriculture can address these issues.

Impact of Food Production on the Environment
Fertilizers. In 1998, the world used 137 million metric tons of chemical
fertilizers, of which U.S. agriculture consumed about 20 million tons, or
15%. Between 1950 and 1998, worldwide use of fertilizers increased more than
10-fold overall and more than 4-fold per person (11,12). Tilman (13)
estimated that crops actually absorb only one-third to one-half of the
nitrogen applied to farmland as fertilizer.

Nitrogen that runs off croplands into the Mississippi River and its
tributaries has been implicated as a major cause of a "dead zone" in the
Gulf of Mexico (14). This zone suffers from hypoxia--a dearth of dissolved
oxygen (< 2 mg/L). Excess nutrients fuel algal blooms by speeding up the
algae's growth-and-decay cycle. This depletes oxygen in the water, killing
off immobile bottom dwellers and driving off mobile sea life such as fish
and shrimp. In 1999, the Gulf's dead zone grew to 20,000 km2 (about the area
of New Jersey), its largest recorded size (15).

Excess nitrogen in soil can lead to less diversity of plant species, as well
as reduced production of biomass. Additionally, some ecologists contend that
this decrease in diversity makes the ecosystem more susceptible to drought,
although this issue has been controversial (16).

Chemical fertilizers can gradually increase the acidity of the soil until it
begins to impede plant growth (17). Chemically fertilized plots also show
less biologic activity in the soil food web (the microscopic organisms that
make up the soil ecosystem) than do plots fertilized organically with manure
or other biologic sources of fertility (18).

Pesticides. Each year the world uses about 3 million tons of pesticides
(comprising herbicides, insecticides, and fungicides), formulated from about
1,600 different chemicals. Complete toxicity data are lacking, however, for
most of these substances. In the United States, insecticide use increased
10-fold between 1945 and 1989 (19).

Some of the increase in pesticide use can be attributed to monocropping
practices, which make crops more vulnerable to pests, but high-volume use
also reflects the imprecise nature of pesticide application. Cornell
entomologist David Pimentel (19) and colleagues stated:

It has been estimated that only 0.1% of applied pesticides reach the target
pests, leaving the bulk of the pesticides (99.9%) to impact the environment.

That environmental impact can include widespread decline in bird and
beneficial insect populations. This can disrupt the balance between predator
and prey because pests often recover faster from pesticide applications than
do the predators that normally keep pest populations under control (20).
Pesticide runoff and airborne pesticide "drift" pollute surface waters and

Some of the more disturbing findings on pesticide impact are as follows:

* The number of honeybee colonies on U.S. farmland dropped from 4.4
million in 1985 to < 1.9 million in 1997, in large part due to direct and
indirect effects of pesticides. Exposure to pesticides can weaken honeybees'
immune systems--making them more vulnerable to natural enemies such as
mites--and can also disrupt their reproduction and development (21,22).
Honeybees are involved in the pollination of at least $10 billion worth of
U.S. crops (23), providing farmers with an essential "natural service."

* A study in the St. Lawrence River Valley in Quebec, Canada, suggests a
link between pesticides and developmental abnormalities in amphibians. Among
other deformities, researchers observed frogs with extra legs growing from
their abdomens and backs, stumps for hind legs, or fused hind legs (24).
Other studies suggest that amphibian deformities may be caused by UV-B
radiation (25) or parasites (26).

* Pesticide exposures have compromised immune function in dolphins,
seals, and whales (27).

Because of the widespread use of pesticides, many target species--whether
insects or plants--develop resistance to the chemicals used against them.
The number of insect species known to display pesticide resistance has
increased from < 20 in 1950 to > 500 as of 1990. Meanwhile, scientists have
identified 273 plant species that exhibit herbicide resistance (28,29).

Soil. Land degradation--and in particular, the deterioration of soils--is
one of the most serious challenges facing humankind as it attempts to feed a
growing population. It takes anywhere from 20 to 1,000 years for a
centimeter of soil to form (30), yet the United Nations has estimated that
wind and water erode 1% of the world's topsoil each year (31).

In 1990, Oldman et al. (32) estimated that since World War II, poor farming
practices had damaged about 550 million hectares--an area equivalent to 38%
of all farmland in use today.

More than 30 years ago, the U.S. Soil Conservation Service recommended that
farmers reduce soil erosion to no more than 5 tons of topsoil per acre per
year (33). Between 1982 and 1997, the average erosion rate fell from 7.3
tons per acre per year to 5 tons (34).

Industrial agriculture also endangers soil health because it depends on
heavy machinery that compacts the soil, destroying soil structure and
killing beneficial organisms in the soil food web (35).

Free-range cattle can have a positive influence on natural ecosystems when
they graze in a sustainable fashion. The U.S. Department of Agriculture
(USDA) Agricultural Research Service found that moderately grazed land (one
cow per 16 acres) had more biodiversity than did ungrazed or heavily grazed
land (36).

When animals graze land heavily they can also cause soil erosion by
compacting the soil and stripping the land of vegetation that holds soil in
place. Feedlot cattle (and industrial animal agriculture in general) destroy
topsoil because growing grain for this industry requires so much cropland.

Land. Most of the world's arable land either is in use for agriculture or
has been used up by (unsustainable) agriculture, most often because
once-fertile soil has been degraded or eroded (37). The world's supply of
arable land per person has been declining steadily (Figure 1).

Figure 1. Average number of hectares of arable land per person, worldwide

An extreme example of land degradation is the phenomenon known as
desertification, which the United Nations has defined as "land degradation
in arid, semi-arid and dry sub-humid areas resulting from various factors,
including climatic variations and human activities" (38). The annual global
cost of desertification has been roughly estimated at $42.3 billion (39).

Desertification reduces the amount of land available for agriculture.
Agriculture can contribute directly to desertification through poor
agricultural practices such as overcultivation, overgrazing, and overuse of
water, and indirectly when land is deforested to create new cropland or new
pastures for livestock. According to the Worldwatch Institute, almost 20
million km2, or 15% of the all land surface, may already be experiencing
some degree of desertification (40).

In the past, increasing demand for grain has been met by two means:
increasing the amount of land used to grow grain and increasing the yields
per land unit. Both avenues to higher grain production have become more
constrained in recent years (41).

The discussion of grain supplies sometimes leaves out the impact of meat
production and consumption on these calculations. A reduction in meat
consumption would help alleviate land scarcity because 37% of the world's
grain, and 66% of U.S. grain production, is fed to livestock (42).

Land planted in cereal grains produces 2-10 times as much protein for human
consumption as land devoted to beef production; for legumes the ratio is
anywhere from 10:1 to 20:1 (43). Yet, in the competition for land in poorer
countries, the cattle industry sometimes crowds out subsistence farmers, who
are then forced to grow food on marginal land. Often, that land is steep and
susceptible to erosion when cultivated (44).

Water. Agriculture affects water resources in two ways: irrigating fields
using surface waters or aquifers diverts water from other potential uses;
and when farming practices pollute surface waters and aquifers, they reduce
the amount of water that is suitable for other uses.

The U.S. Environmental Protection Agency has blamed current farming
practices for 70% of the pollution in the nation's rivers and streams. The
agency reports that runoff of chemicals, silt, and animal waste from U.S.
farmland has polluted more than 173,000 miles of waterways (45).

Agriculture accounts for about two-thirds of all water use worldwide, far
exceeding industrial and municipal use (46) (Figure 2). In many parts of the
world, irrigation is depleting underground aquifers faster than they can be
recharged. In other cases, agriculture depends upon "fossil aquifers" that
mostly contain water from the last ice age. These ancient aquifers receive
little or no recharge, so any agriculture that depends upon them is
inherently unsustainable.

Figure 2. Global water use, by sector, based on 1990 figures. Adapted
from Postel (46).

The Ogallala Aquifer covers parts of eight states in the U.S. Midwest and is
a critical resource for the region's agriculture. The aquifer receives
little recharge, and its water table is dropping as much as 1 m/year (30).
It has been estimated that in another decade or two the aquifer will be so
low that its use for irrigation will become prohibitively expensive (41).

Irrigation has been used to turn many low-rainfall regions into agricultural
wonders--at least in the short term. One-third of all the food we grow comes
from the one-sixth of cropland that is irrigated (33). However, excessive
irrigation can exact an ecologic price, through waterlogging and
salinization. Irrigation water leaves behind salts that slowly diminish the
soil's productivity. The Food and Agriculture Organization of the United
Nations (FAO) estimates that about 13% of the world's irrigated land is
either waterlogged or excessively salty, and another 33% is affected to some
degree. Salinization affects 28% of the irrigated land in the United States
and 23% in China, for example (47). According to hydrologist Daniel Hillel
(33), many of the problems with irrigation arise from careless practices
such as overwatering. He advocates modernizing the irrigation systems in
developing countries, where the most acute irrigation problems exist.

Water use in irrigation is extremely inefficient: the FAO estimates that
crops use only 45% of irrigation water (47). In the case of China's Yellow
River, only 30% of the water extracted for irrigation actually reaches
crops. Agriculture extracts 92% of the water taken from the river, which in
1997 failed to reach the sea for 226 days, its worst dry spell ever
recorded. Since the 1950s, the amount of land irrigated with water from the
Yellow River has more than tripled (48).

In parts of the United States, much of the water used for irrigation serves
the livestock sector. For example, the beef feedlots of Colorado, Kansas,
Nebraska, and the Texas panhandle get their feed grain from irrigated
agriculture that relies on diminishing groundwater supplies. Beef production
requires large volumes of water--as much as 100 times that required to
produce equivalent amounts of protein energy from grains (49).

Energy. Converting grain into meat entails a large loss of food energy,
particularly if cattle are doing the converting. Conservative estimates are
that cattle require 7 kg of grain to create 1 kg of beef, compared with
about 4 kg for pork and just over 2 kg for chicken (50).

Fossil fuel energy is also a major input to industrial agriculture. The food
production system accounts for 17% of all fossil fuel use in the United
States, and the average U.S. farm uses 3 kcal of fossil energy in producing
1 kcal of food energy. Meat production uses even more energy. In the typical
feedlot system--where a little more than one-half of the cattle's feed is
grain--the fossil energy input is about 35 kcal/kcal of beef protein
produced (37).

In addition, the road from the farm to the dinner plate is an
energy-intensive one because transporting, processing, and packaging our
food require large amounts of fuel. For instance, before arriving at the
Jessup (Maryland) Terminal Market, vegetable shipments travel, on average,
about 1,600 miles and fruit shipments about 2,400 miles (51). Some estimated
energy inputs for processing various foods are 575 kcal/kg for canned fruits
and vegetables, 1,815 kcal/kg for frozen fruits and vegetables, 15,675
kcal/kg for breakfast cereals, and 18,591 kcal/kg for chocolate (37).

A 1969 study by the Department of Defense estimated that the average
processed food item produced in the United States travels 1,300 miles before
it reaches consumers (52). Processing accounts for about one-third of the
energy use in the U.S. food system, and each calorie of processed food
consumes about 1,000 calories of energy (52). In all likelihood, the food
system has become more energy intensive since the time of this study.

Biodiversity. Agriculture is dependent on biodiversity for its existence
and, at the same time, is a threat to biodiversity in its implementation.
One way that agriculture depends on biodiversity is in developing new
varieties of plants that keep pace with ever-evolving plant diseases. When
plant breeders need to find a resistance gene to improve a domestic variety,
they sometimes cross-breed the variety with a wild relative. However,
because they are under pressure to bring a product to market quickly, plant
breeders usually search for a single gene that confers resistance. This
practice is risky, as Cary Fowler and Pat Mooney explain in Shattering:
Food, Politics, and the Loss of Genetic Diversity (53):

Frequently, resistance in a traditional landrace [wild variety] is not
nearly so simple [as one gene]. Resistance may be the product of a complex
of genes, literally hundreds of genes working together.... By utilizing
one-gene resistance ... the plant breeder gives the pest or disease an easy
target. It has only to overcome or find a way around that one line of
defense.... The use of one gene for resistance, one gene which is routinely
overcome by pest or disease, results in that gene being "used up." It no
longer provides resistance.

It may have taken thousands of years for a wild plant to develop its complex
of resistance genes, but modern plant breeding methods are chipping away at
this natural resource--one resistance gene at a time--and at a rate beyond
nature's ability to replenish it (54).

The practice of monocropping or monoculture--planting the same crop over a
large land area--creates greater necessity for quick-cure plant breeding.
Insect pests and plant diseases are both aided by monocropping if a crop
variety that may be susceptible to a plant disease or insect pest is planted
contiguously and in great volume.

Industrial agriculture erodes biodiversity not only because it favors
monocultures but also because those monocultures replace diverse habitats.
One example is the way rice monocultures crowd out local wild varieties. In
the Philippines, Indonesia, and some other developing countries, more than
80% of farmers now plant modern rice varieties. In Indonesia, this led to
the recent extinction of 1,500 local rice varieties in just 15 years (55).

Another threat to biodiversity is the continued consolidation of the seed
industry and the effect it is having on the availability of nonhybrid plant
varieties. As of 1998, the 10 largest seed companies controlled 30% of the
global market (56). Large seed companies tend to rely on first-generation
hybrids because they force growers to buy new seed every year. As the
industry has consolidated, traditional varieties have been removed from seed
catalogs at an alarming rate. In 1981, nearly 5,000 nonhybrid vegetable
varieties were being sold through mail-order catalogs; by 1998, 88% of those
varieties had been dropped (57).

The dependence of industrial agriculture on synthetic chemicals has reduced
biodiversity in the insect world, as well. Pesticides kill wild bees and
other beneficial species that are nontarget victims. Managed pollination--a
$10 billion a year industry in the United States and Canada--relies on just
two species of bee. In contrast, North America has 5,000 wild bee species,
but these have mostly disappeared from agricultural lands, due primarily to
pesticides, a lack of floral diversity, destruction of habitats, and
competition with managed pollinators (58).

Excessive fertilizer use also reduces biodiversity because of the effect
that nitrogen runoff is having on ecosystem balance. A minority of species
can thrive in high-nitrogen environments, and these sometimes crowd out all
other species in the ecosystem (59).

Global warming and climate change. Agriculture is directly responsible for
about 20% of human-generated emissions of greenhouse gases, according to
estimates by the Intergovernmental Panel on Climate Change. Changes in land
use contribute about 14% of the total human-generated emissions of
greenhouse gases, and much of this land development is for agricultural
purposes (60).

Industrial animal production. Animals have traditionally played an important
role in agriculture, not only as a source of food but also as a way to
recycle nutrients and build soil organic matter. Their manure deposited on
croplands or rangelands helps build the fertility of the soil.

In recent decades, however, industrial agriculture has increasingly
separated animals from the land. More and more meat production is occurring
in concentrated operations commonly called factory farms.

The manure output from these factory farms overwhelms the capacity of local
croplands to absorb it. The USDA has estimated that animals in the U.S. meat
industry produced 1.4 billion tons of waste in 1997, which is 130 times the
nation's volume of human waste--or 5 tons of animal waste for every U.S.
citizen (61).

By concentrating thousands of animals into a small area, industrial animal
production creates threats to both the environment and human health. Despite
this, the trend in the meat industry has been toward greater concentration
of livestock. Fewer and fewer farms are raising animals, and the average
number of animals per farm is going up.

For example, between 1967 and 1997 the number of hog farms in the United
States declined from over a million to just 157,000. The largest 3% of farms
(all with at least 1,000 hogs each) now produce 60% of U.S. hogs (61,62).

According to Copeland and Zinn (62), the story is similar in poultry and
beef output:

Broiler production nearly tripled between 1969 and 1992, while the number of
farms with broiler houses dropped by 35%.... Firms with more than 100,000
broilers accounted for 70% of all sales in 1975, but now account for more
than 97% of sales.

In beef, more than 40% of all production comes from 2% of the feedlots (61).

Because the huge volume of manure from factory farms cannot be absorbed by
local croplands, the industry stores it in open pits--euphemistically called
"lagoons" by the industry--that are prone to spills. Animal waste is a major
contributor to the excessive nutrient loading that is suspected of causing
outbreaks of Pfiesteria piscicida and large fish kills in North Carolina
waters and in the Chesapeake Bay in recent years (61,63).

By concentrating hundreds or thousands of animals into crowded indoor
facilities, factory farms raise ethical issues about their treatment of
animals. Each full-grown chicken in a factory farm has as little as 0.6 ft2
of space. Crowded together in this way, chickens become aggressive toward
each other and sometimes even eat one another. For this reason, factory
farms subject them to painful debeaking (64).

Hogs, too, become aggressive in tight quarters and often bite each other's
tails. In response, factory farmers often cut off their tails. Concrete or
slatted floors allow for easy removal of manure, but because they are
unnatural surfaces for pigs, they result in skeletal deformities of the legs
and feet (65). Ammonia and other gases from the manure irritate animals'
lungs, making them susceptible to pneumonia. Researchers from the University
of Minnesota found pneumonia-like lesions on the lungs of 65% of 34,000 hogs
they inspected (66).

Factory farms chain veal calves around the neck to prevent them from turning
around in their narrow stalls. Movement is discouraged so that the calves'
muscles will be underdeveloped and their flesh will be tender. They are kept
in isolation and near or total darkness during their 4-month lives and are
fed an iron-deficient diet to induce anemia so that their flesh develops the
pale color prized in the marketplace (65).

Genetically engineered crops. Genetically engineered crops have been on the
market only since 1996, but already they occupy 130 million acres worldwide,
including a 19% increase in acreage in 2001. This includes 88 million acres
in the United States (67).

Transgenic crops have been defined as genetically engineered to contain
traits from unrelated organisms. In traditional plant breeding, a desired
trait must be obtained from a closely related species that will breed with
that plant through natural mechanisms, but genetic engineers can search for
the desired trait anywhere in the plant or animal kingdom (68).

Introducing genes into crops in this novel way raises ethical,
environmental, and health concerns. In this paper we do not discuss the
ethics of transgenic crops, but we review the health issues in "Impact of
Food Production and Diet on Health" below.

The environmental concerns raised by genetically engineered crops include
the following:

* Gene transfer to wild relatives: Herbicide-resistance genes engineered
into crops can spread to wild relatives of those crops. The FAO has said
this "could create super-weeds and make weed control more difficult" (69).

* Increased herbicide use: The most common reason for manipulating crop
genes is to confer resistance to commercial herbicides. Increased use of
genetically engineered crops of this sort will likely be accompanied by
increased use of the relevant herbicides (69). Weeds would therefore be
exposed to more herbicide, helping them develop herbicide resistance more

* Insect resistance to Bacillus thuringiensis (Bt) toxin: The second most
popular reason for genetically engineering crops is to give them resistance
to insects, viruses, and fungi. Genetic engineers have produced insect
resistance in corn, rice, cotton, tobacco, and many other crops by
introducing a gene that produces the Bt toxin. In other words, the plant
gives off its own pesticide, so farmers do not need to apply pesticides. In
nature, the soil bacterium B. thuringiensis produces the Bt toxin. The
widespread use of Bt crops would in all likelihood hasten the development of
Bt resistance in insects that are currently vulnerable to this natural pest
control method. This would eliminate an important organic pest control
method often used by organic growers as a last resort (68). Bt crops may
also pose risks for nontarget species. Two recent studies reported that
pollen from Bt corn can be deadly for monarch butterfly larvae (70,71).

Impact of Food Production and Diet on Health
The preceding section describes the environmental harms caused by our
dominant food production system. Industrial food production methods--and
some of the foods they produce--are also causing both acute and chronic
disease in humans. Among the problems are the following:

* Animal-based foods contribute to chronic diseases.
* Pesticide residues enter our bodies through air, water, and food and
raise risks for certain cancers as well as reproductive and endocrine system
* Concentrated, high-speed meat production leads to a greater risk from
foodborne pathogens, some of them newly emerging.
* Excessive use of antibiotics in animal agriculture may create resistant
strains of microbes in humans.

In this section we discuss many comparison studies of the diets of various
population groups and their health outcomes.These epidemiologic studies have
methodologic deficiencies, in that most data sources are not sufficiently
comprehensive to eliminate the effects of all possible confounding variables
during multivariate analysis. However, in cases where the body of
epidemiologic evidence is substantial and/or the disparities are large,
these comparisons still provide results worthy of our consideration.

Diet and Disease

We have evidence that large quantities of saturated fat in the diet
contribute to the chronic degenerative diseases that are the most common
causes of death in affluent societies. Animal-based diets, which are high in
saturated fat, dominate in the West and are on the increase in many
developing countries.

Although undernutrition is still common in developing countries (affecting
about 800 million people worldwide), in affluent countries the main causes
of death are associated with overnutrition. In the United States, for
example, the average adult male consumes 154% of the recommended daily
allowance (RDA) for protein (97 g vs. an RDA of 63 g), and the average adult
female consumes 127% of the RDA (63.5 g vs. an RDA of 50 g) (72,73). The
average American derives 67% of protein from animal sources, compared to a
34% average worldwide (37). Meanwhile, the World Health Organization (WHO)
estimates that > 40% of children (or 230 million) in poor countries are
stunted by undernutrition (74).

According to the U.S. Surgeon General (75), the "preponderance" of
scientific evidence strongly suggests that

a dietary pattern that contains excessive intake of foods high in calories,
fat (especially saturated fat), cholesterol, and sodium, but that is low in
complex carbohydrates and fiber, is one that contributes significantly to
the high rates of major chronic diseases among Americans.

Animal products contain no fiber and almost no complex carbohydrates. Animal
products are also the only source of cholesterol in the diet, and they
contribute most of the saturated fat in the typical U.S. diet. On the other
hand, vegetarian diets are associated with lower rates of chronic disease.
According to the American Dietetic Association (76),

A considerable body of scientific data suggests positive relationships
between vegetarian diets and risk reduction for several chronic degenerative
diseases and conditions, including obesity, coronary artery disease,
hypertension, diabetes mellitus, and some types of cancer.

Cardiovascular disease. Diseases of the circulatory system account for
almost one-half of all deaths in the developed world, according to the WHO
(77). Mortality from circulatory system disease has been falling in affluent
countries in recent years but it is increasing in newly industrializing
countries that are adopting "Western" diet patterns (77). This increase in
"diseases of affluence" in newly industrializing countries parallels the
increasing consumption of animal-based foods (as well as higher smoking
rates and greater urbanization).

In 1999, the average U.S. citizen consumed 124 kg (273 pounds) of meat. By
contrast, average meat consumption for all industrialized countries is 77
kg/person, and for all nonindustrialized countries it is 27 kg. Since 1961,
U.S. per capita meat consumption has increased by 40% (4) (Figure 3).

Figure 3. Average meat consumption in selected countries in 1999 and
averages for all industrialized and developing countries (4).

Cardiovascular disease is the leading cause of death in the United States,
and one of the major risk factors is a high cholesterol level in the blood.
The human body manufactures all the cholesterol it needs, and any
cholesterol acquired through diet comes from animal foods because plant
foods contain no cholesterol (78).

Consumption of animal foods elevates a person's cholesterol level, and this
in turn elevates the person's risk for heart attack, stroke, and arterial
disease. Whereas the average cholesterol level among heart attack victims is
244 mg/dL of blood serum, heart attack risk falls to virtually zero when the
cholesterol level is less than 150 mg/dL (79). As of 1990, the average
cholesterol level in the United States was 205 mg/dL (78).

Vegetarians who avoid meat but consume dairy products and/or eggs have lower
cholesterol levels than do omnivores. Still lower are cholesterol levels in
vegans, people who refrain from eating any animal products. One
meta-analysis found that in nine comparison studies, vegans had an average
cholesterol level of 158 mg/dL, vegetarians 182 mg/dL, and omnivores 193
mg/dL (80). Vegetarians also have lower-than-average mortality in general,
and this is attributed mostly to their lower rates of heart disease and
certain cancers (80).

Cancer. Diets that are high in fat and low in fiber are associated with an
increased risk of colon cancer (81). In addition to being high in fat, meat
and dairy products contain no fiber.

In contrast, many epidemiologic studies have found that high fiber intake
leads to lower risk of not only colon cancer but also breast and prostate
cancer (80). Prostate cancer has been linked to high intakes of calories,
total fat, and milk, meat, and poultry (82).

Lung cancer is also less prevalent in vegetarians, even when one controls
for the effects of smoking (83).

Countries with high rates of fat consumption have the highest breast and
colon cancer mortality, whereas the lowest death rates from these diseases
occur in populations with the lowest levels of fat consumption (84).

Diabetes. Seventh Day Adventists are overwhelmingly vegetarian or
near-vegetarian, so researchers and others often compare their health
outcomes with those of the general population. One study (80) found that
rates of diabetes in Seventh Day Adventists were 45% of rates in all U.S.
white adults, and that type II (non-insulin-dependent) diabetes correlated
positively with obesity and fat and protein intake. Vegetarians have lower
rates of these risk factors (80).

Treatment programs for diabetics now recommend drastic reductions in
consumption of meat, dairy products, and oils but increased consumption of
grains, legumes, and vegetables.

Medical costs of meat consumption. Barnard et al. (85) estimated that meat
consumption costs the United States roughly $30-60 billion a year in medical
costs. The authors made this calculation (which they considered a
conservative one) on the basis of the estimated contribution that eating
meat makes to the diseases discussed above, plus other chronic diseases
common in affluent countries and foodborne illnesses linked to meat

Pesticides and Health
Pesticides produce both short- and long-term effects on human health. The
United Nations has estimated that about 2 million poisonings and 10,000
deaths occur each year from pesticides, with about three-fourths of these
occurring in developing countries (86). The long-term effects of pesticides
include elevated cancer risks and disruption of the body's reproductive,
immune, endocrine, and nervous systems. Population-based studies have shown
associations between certain types of pesticide and certain cancers (Table

Pesticides can suppress the immune system. In a 1996 report, Repetto and
Baliga (27) cite epidemiologic evidence of an association between pesticide
exposure and increased incidence of human disease, particularly those
diseases to which immunocompromised individuals are especially prone (27).

The list of pesticides that are suspected endocrine disruptors includes
atrazine and alachlor, two of the most commonly applied herbicides on corn
and soybean crops in the United States. Just over one-half of the herbicides
used in the United States in 1991 were applied to corn, soybeans, or cotton

Many pesticides have not been tested for their toxicity, and testing in the
past has focused on acute effects rather than long-term effects. In an
inventory of commonly used chemicals in 1984, the National Research Council
found that data required for complete health hazard evaluations were
available for only 10% of pesticides (89).

Human exposure to pesticides can come through residues in food--either on or
within fruits and vegetables, or in the tissues of fish and animals we
eat--through contaminated drinking water, and through the air we breathe
(because of "pesticide drift" from the spraying of fields or lawns).

Some pesticides accumulate up the food chain, or "bioaccumulate." A 1967
study found that DDT levels were 20,000 times higher in one fish species
than they were in the surrounding sea water, and 520,000 times higher in
fish-eating cormorants (90). So, when humans eat foods higher on the food
chain (more meat, milk, cheese, and eggs and fewer plant foods), they
increase their exposure to bioaccumulated pesticides.

Industrial Food System and Public Health
The production and processing of food are increasingly concentrated (fewer
owners and larger operations), automated, and fast-paced, which has
implications for public health. Among the major problems:

* Pollution from factory farms is harming the health of both workers and
residents living downstream or downwind from these operations.
* New strains of foodborne pathogens (e.g., Listeria and toxigenic
Escherichia coli) have emerged in recent years, and long recognized
pathogens have been causing more widespread harm.

* The nonmedical use of antibiotics in animal agriculture may be
threatening the effectiveness of antibiotics in treating human disease by
creating selective pressure for the emergence of antibiotic-resistant
* Genetically engineered foods present risks of new allergens in the food
supply and may be harmful to immune systems and vital organs.
* These phenomena are due, in part, to production and processing methods
that emphasize economic efficiency but do not give sufficient priority to
public health or the environment.

Factory farming and human health. Gases from animal manure at factory farms
create potential human health risks for workers and residents living
downwind, and manure runoff can damage local water quality by overloading it
with nutrients, particularly phosphates.

Factory farms store manure from animal confinement buildings either in pits
underneath the buildings or in nearby open-air pits, often extending over
several acres. Farmers and farm workers have died from asphyxiation after
entering underground pits used for storing animal manure (91).

The prevalence of occupational respiratory diseases (occupational asthma,
acute and chronic bronchitis, organic dust toxic syndrome) in factory farm
workers can be as high as 30% (92). A University of Iowa study found that
people living near large-scale hog facilities reported elevated incidence of
headaches, respiratory problems, eye irritation, nausea, weakness, and chest
tightness (93).

Manure runoff from factory farms is among the suspected causes of outbreaks
of Pfiesteria piscicida in Maryland, Virginia, and North Carolina. The human
health effects have included acute short-term memory loss, cognitive
impairment, asthmalike symptoms, liver and kidney dysfunction, blurred
vision, and vomiting (94).

Water polluted with manure runoff has other health implications. A Senate
report (61) noted that

Manure contains pathogens to which humans are vulnerable, including
Salmonella and Cryptosporidium, and can pollute drinking water with
nitrates, potentially fatal to infants. More indirectly, microbes that are
toxic to animals and people are thought to thrive in waters that have
excessively high levels of nutrients from sources including animal waste

Foodborne pathogens. The U.S. Centers for Disease Control and Prevention
(CDC) have estimated that foodborne diseases cause approximately 76 million
illnesses, 325,000 hospitalizations, and 5,000 deaths in the United States
each year. Of the approximately 1,800 deaths attributed to known pathogens,
more than 75% are blamed on Salmonella, Listeria, and Toxoplasma (95). All
three pathogens are transmitted to humans primarily through meat.

Two bacteria commonly found on meat--Campylobacter and Salmonella--cause
more than 3 million foodborne illnesses in the United States each year (95).
These bacteria occur naturally on chickens and are not always harmful to
them, but in humans they can cause severe diarrhea and nausea and
occasionally produce fatal disease. The crowded conditions of factory farms
increase the level of contamination, and the high-speed, automated methods
of slaughtering and processing the animals make it difficult to detect that

Much less common but more deadly than the bacteria mentioned above are the
newly emerging strains of toxigenic E. coli and Listeria. The CDC puts the
annual disease burden for E. coli at about 62,000 illnesses and 50 deaths,
and blames Listeria for about 2,500 illnesses and 500 deaths (95).

Infection with the enterohemorrhagic strain of E. coli (O157:H7) was first
discovered in 1975. The pathogen causes bloody diarrhea and acute renal
failure and is sometimes fatal; children and the elderly are at greatest
risk. E. coli O157:H7 is most often spread by undercooked ground beef or raw
milk (96).

Listeria monocytogenes is referred to as an emerging pathogen because only
recently has food been recognized to play a role in its spread. According to
the U.S. Food and Drug Administration, infections with Listeria can cause
abortion and stillbirth, and blood poisoning or meningitis in infants and
immune-deficient persons. Listeria is most often associated with consumption
of certain dairy products and processed meats (97).

Another newly emerging concern about the food supply is a neurologic disease
in cattle known as bovine spongiform encephalopathy (BSE). According to the
WHO (98), a new variant of Creutzfeldt-Jakob disease, a degenerative
neurologic disease in humans, has a strong link to exposure to BSE, probably
through the food supply. BSE was first recognized in cattle in 1986, and
epidemiologic studies suggest that cattle feed prepared from carcasses of
dead ruminants was the source of the disease (98).

Antibiotics in animal agriculture. Seventy percent of U.S.-produced
antibiotics are fed to animals to promote growth (99). Excessive use of such
drugs in animals can enhance the development of drug-resistant strains of
disease, which can then be transmitted to humans through the food supply.

The National Research Council and Institute of Medicine (100) have noted
that there is

a link between the use of antibiotics in food animals, the development of
bacterial resistance to these drugs, and human diseases--although the
incidence of such disease is very low.

The WHO has called for reduced use of antibiotics in animal agriculture,
noting that resistant strains of Salmonella, Campylobacter, Enterococci, and
E. coli have been transmitted from animals to humans (101).

Genetically engineered foods. Only recently have genetically engineered
foods been introduced into the human food supply. One of the concerns
surrounding genetic engineering of foods is that new allergens could be
introduced into the food supply because the sources for genetically
engineered material may include organisms not previously eaten by humans
(102). In addition, it will be harder for people with food allergies to
avoid consuming an offending food if proteins from that food are integrated
into a food to which they are not allergic. For example, soybeans that were
genetically engineered to contain proteins from Brazil nuts caused reactions
in individuals who were allergic to Brazil nuts (103).

Antibiotic resistance genes are used as markers in the genetic engineering
of foods. This practice raises two possible concerns: eating such foods soon
after taking antibiotics could reduce or eliminate the drugs' effectiveness
because enzymes produced by the resistance genes can break down antibiotics;
and resistance could be transferred to disease organisms in the digestive
tract, making it harder to treat them with antibiotics. But there is
disagreement over these issues within the scientific community, and more
research is under way (104,105).

Sustainable Agriculture
Unsustainability in agriculture is not a new issue. Large civilizations have
risen on the strength of their agriculture and subsequently collapsed
because their farming methods had eroded the natural resource base (106).
Today's conventional or industrial agriculture is considered unsustainable
because it is similarly eroding natural resources faster than the
environment can regenerate them and because it depends heavily on resources
that are nonrenewable (e.g., fossil fuels and fossil aquifers).

One of the goals of the sustainable agriculture movement is to create
farming systems that mitigate or eliminate environmental harms associated
with industrial agriculture. Sustainable agriculture is part of a larger
movement toward sustainable development, which recognizes that natural
resources are finite, acknowledges limits on economic growth, and encourages
equity in resource allocation.

Sustainable agriculture gives due consideration to long-term interests
(e.g., preserving topsoil, biodiversity, and rural communities) rather than
only short-term interests such as profit. Sustainable agriculture is also
place specific. For example, a farming system that is sustainable in a
high-rainfall area may not be sustainable in an arid climate. Sustainable
agriculture is dynamic, meaning that it must evolve to respond to changes in
its physical environment or its social or economic context. Sustainable
agriculture is holistic in that it takes a systemwide approach to solving
farm management problems, and also because it places farming within a social
context and within the context of the entire food system.

Sustainable agriculture has been defined in several ways, for example:

* Sustainable agriculture integrates three main goals--environmental
health, economic profitability, and social and economic equity....
Sustainability rests on the principle that we must meet the needs of the
present without compromising the ability of future generations to meet their
own needs (107).

* Sustainable agriculture is a model of social and economic organization
based on an equitable and participatory vision of development which
recognizes the environment and natural resources as the foundation of
economic activity. Agriculture is sustainable when it is ecologically sound,
economically viable, socially just, culturally appropriate, and based on a
holistic scientific approach (108).

* Sustainable agriculture does not refer to a prescribed set of
practices. Instead, it challenges producers to think about the long-term
implications of practices and the broad interactions and dynamics of
agricultural systems. It also invites consumers to get more involved in
agriculture by learning more about and becoming active participants in their
food systems. A key goal is to understand agriculture from an ecological
perspective--in terms of nutrient and energy dynamics, and interactions
among plants, animals, insects and other organisms in agroecosystems--then
balance it with profit, community and consumer needs (109).

Sustainable methods. Although no one set of farming practices constitutes
sustainable agriculture, we briefly describe here certain methods that
enhance sustainability.

* Crop rotation. By rotating two or more crops in a field, farmers
interrupt pests' reproductive cycles and reduce the need for pest control
(110). Rotations sometimes reduce the need for added fertilizer because one
crop provides nutrients for the next crop.

* Cover crops. Cover crops are planted to improve soil quality, prevent
soil erosion, and minimize weed growth. Some cover crops can also generate

* No-till and low-till farming. These farming systems are based on the
premise that minimizing disturbances to the soil will increase the retention
of water, nutrients, and the topsoil itself. Between 1980 and 1993, the
amount of land under conservation tillage increased from < 15% to about 35%
of all U.S. farmland (111).

* Soil management. Good stewardship of the soil involves managing its
chemical, biologic, and physical properties. Industrial agriculture has
tended to emphasize the chemical properties of soil, to the detriment of the
other two. An acre of healthy soil can contain 4 tons of organisms, which
make up the soil's ecosystem (112). Organic matter and compost are food for
beneficial bacteria, fungi, nematodes, and protozoa. If managed properly,
these soil organisms perform vital functions that aid in plant growth (113).
Healthy soil produces plants that are more vigorous and therefore less
susceptible to pests.

* Diversity. Growing a variety of crops provides a buffer against both
ecologic and economic problems. Monocultures are more vulnerable to pests as
well as to fluctuations in market price. Crop variety can also create more
niches for beneficial insects (107).

* Nutrient management. After monitoring the soil content of nitrogen and
other nutrients, farmers can prevent runoff into adjacent waters--and also
save money on purchased fertilizers--by applying only what the plants and
soil can absorb, with no excess.

* Integrated pest management. An integrated pest management (IPM) system
prefers biologic methods and uses (least-toxic) chemical pesticides only as
a last resort. To keep destructive insects under control, an IPM emphasizes
crop rotations, intercropping, and other methods of disrupting pest cycles,
as well as plant varieties that have high resistance to pests. IPM also uses
insect predators, as well as biopesticides such as Bt (114). As of 1994,
coordinators of the federal IPM program were reporting that

more than 40,000 farmers in 32 states have made significant reductions in
their use of synthetic chemical pesticides by implementing practices
associated with sustainable agriculture (115).

* Rotational grazing. By continually moving animals to different grazing
areas, rotational grazing prevents soil erosion by maintaining sufficient
vegetative cover. It also saves on feed costs, averts the manure buildup of
concentrated animal feeding operations, and contributes to soil fertility.

Barriers to sustainability. If our current agricultural system is so harmful
and unsustainable, why is it being perpetuated? Most important, powerful
economic interests benefit from the status quo in agriculture. Industrial
agriculture relies heavily on external inputs (e.g., synthetic chemical
fertilizers and pesticides, machinery, fossil fuels), which mean costs for
farmers but profits for farm input industries.

Farmers use such inputs because they promise greater yields from their
crops, but greater yields have been a mixed blessing, according to
agricultural economist John E. Ikerd (116):

Over most of the past century, profits from farming have gone primarily to
those who found ways to reduce costs first and expand production the
fastest. However, each new round of cost cutting technology has resulted in
increased production and lower prices, erasing initial profitability.

Thus, the quest for greater yields has landed farmers on a technologic
treadmill of increasing inputs and decreasing profit margins.

Increasing dependence on off-farm resources and distant markets has caused
much of the profitability of agriculture to shift from the farmer to the
industries that supply the inputs and market the outputs. Madden and
Chaplowe (108) estimate that between 1910 and 1990, the share of the U.S.
agricultural economy going to farmers declined from 41% to 9%, while the
marketing and farm input industries' shares increased by similar amounts

As farmers' profit margins shrink, some farmers choose to enlarge their
operations to compensate. Invariably, this means some farmers get pushed out
of business. For example, in the hog industry, about one-fourth of all U.S.
producers went out of business between 1998 and 2000 (117), leaving only 50
producers controlling one-half of all hog production (118).

The trend toward large-scale farming has implications for the economic
health of rural communities. Studies have shown that independent hog farmers
produce more jobs, more local retail spending, and more local per capita
income than do larger corporate operations (62). Profits generated by
small-scale producers (of hogs or any other commodity) are more likely to
remain in the community and create multiplier effects in the local economy.

Despite these benefits of small farms, U.S. agricultural subsidies flow
disproportionately to large farms. The International Institute for
Sustainable Development (8), based in Winnipeg, Canada, reports that

Almost 30% of subsidies go to the top 2% and over four-fifths to the top
30%. Ironically, if the United States government were to shift its target
from the top 30% to the bottom 70% of farmers, it could save at least $8
billion a year while supplying a competitive boost to lower-income farms.

Government subsidies often help perpetuate unsustainable practices. For
example, one of the largest beneficiaries of federal agricultural subsidies
are the cattle ranchers whose animals graze on federal lands for less than
one-third the price they would pay on private land. Total subsidies in the
federal grazing program cost taxpayers at least $500 million a year, not
counting the cost of the environmental degradation caused by overgrazing

Subsidies often stimulate greater use of chemical inputs, despite their
environmental and public health harms. Rice farmers in Japan, Taiwan, and
Korea use just over one-half of all insecticides applied to rice worldwide
yet produce only 2% of the world's crops. The reason is that large
government price supports ($13 billion worth in Japan) make it profitable to
increase insecticide use even when the resulting production gains are small

Besides encouraging harmful practices, farm subsidy programs often fail to
reward good stewardship. They tend to emphasize a handful of major crops and
"put resource-conserving crop rotations at a financial disadvantage" (120).
Farmers receive no government incentives for sustainable practices such as
growing clover or alfalfa to enhance soil fertility (120).

Governments also help perpetuate chemical-intensive agriculture by funding
research on chemical fixes for agricultural problems, to the exclusion of
research on more sustainable options. Of 30,000 agricultural research
projects on the USDA's Current Research Information System for 1995, only 34
had a strong organic focus (121).

Adopting sustainable methods. Government programs, research, and other
factors can influence moves toward sustainability in agriculture, but
ultimately this shift also involves decisions by individual farmers. Some
farmers will be motivated to change because of environmental concerns, but
we also need to reassure farmers that sustainable methods are economically
viable. Comparisons between conventional (industrial) and sustainable
agriculture systems can be complicated, but those that exist describe
sustainable practices as "highly productive and economically competitive"

In the early 1990s, the Gallo Wine Company (Sonoma County, CA) shifted 6,000
acres of wine grapes from conventional to organic methods. After a
transition phase during which production was more expensive, Gallo was
producing yields equivalent to those produced by its previous chemical
methods but at a lower cost per acre (115).

Sustainable systems are especially apt to compare favorably with
conventional systems when the comparison includes a full-cost accounting of
the environmental and public health harms and benefits of each system. For
example, if a conventional system were to produce higher yields per acre
than a sustainable one but also degrade local water supplies because of
pesticide or fertilizer runoff, the benefits of the higher yield may be
offset by the cost of environmental cleanup (costs that are usually
"externalized," meaning they are paid by society rather than the polluter).

Other factors that influence adoption of sustainable practices are land
ownership and the age of the farmer. According to an FAO report (122),

Land tenure is ... critical to the adoption of organic [free of synthetic
chemicals] agriculture. It is highly unlikely that tenant farmers would
invest the necessary labour and sustain the difficult conversion period
without some guarantee of access to the land in later years when the
benefits of organic production are attainable.

Urban agriculture. The world is becoming increasingly urbanized. The United
Nations has estimated that world population will increase by about 2 billion
people in the next 30 years, and all of that growth is expected to occur in
urban areas (population growth plus continued migration to cities) (123).
This makes urban agriculture an increasingly important component of
agricultural sustainability.

Because it produces closer to consumers, urban agriculture reduces energy
costs and pollution from transport and storage and reduces packaging and
spoilage. It also offers a viable use for urban waste (such as wastewater
for irrigation), creates economic development, and improves food security in
poor communities (124).

Alternative marketing. Farmers can capture more of the profitability of
agriculture through value-added products or direct marketing strategies such
as farmers markets and community-supported agriculture (CSA). In the CSA
model, consumers purchase a "share" in a farm and receive a portion of its
harvest. This gives farmers more working capital at the beginning of the
growing season and a guaranteed market at the end. Consumers develop a
direct link to their food supply and have input into production decisions.
CSAs have helped keep many small farms in business (125). Meanwhile, farmers
markets have enjoyed rapid growth in the United States. Between 1994 and
2000, the number of U.S. farmers markets increased by 63%, from 1,755 to
2,863 (126).

Hunger and food insecurity are currently problems not of resource scarcity
but of insufficient political will or moral imperative to change the way
food is allocated--Pinstrup-Anderson et al. have estimated that the
developing world alone is producing enough food to provide every person with
> 2,500 calories/day (127). If unsustainable agriculture remains the norm,
however, scarcity of resources could soon become a major factor in food

Coupled with energy- and resource-intensive food production methods, rising
population and rising per capita consumption are bringing us closer to the
limits of the planet's ability to produce food and fiber for everyone. The
world's fisheries may be putting out a warning signal about nature's limits.
The FAO reported that "11 of the world's 15 most important fishing areas and
70% of the major fish species are either fully or overexploited" (128).

The United Nations' most recent midrange projection is that the world
population will increase to 9.3 billion by 2050 (129). The world's
population is rapidly becoming more urbanized. In 1975, about one-third of
the world's people lived in cities (130); by 2030, that figure is expected
to rise to > 60% (131). Both population growth and urbanization bode ill for
the environment and the social order that it upholds. To meet their need for
food and other goods, the additional people will make further demands upon
finite resources such as arable land, fertile soil, and freshwater.

When people move from rural to urban areas, they characteristically increase
their consumption, including the amount of animal products they consume.
Thus, the combination of more people and greater consumption per capita are
creating a threat of future scarcity in vital resources.

These problems are complex and have no single solution, which leaves many
people feeling powerless to affect them.

One personal act that can have a profound impact on these issues is reducing
meat consumption. To produce 1 pound of feedlot beef requires about 2,400
gallons of water and 7 pounds of grain (42). Considering that the average
American consumes 97 pounds of beef (and 273 pounds of meat in all) each
year, even modest reductions in meat consumption in such a culture would
substantially reduce the burden on our natural resources.

For the United States and other industrialized nations, lowered meat
consumption would yield significant public health benefits, particularly a
reduction in heart disease, several cancers, and other chronic diseases.
These diseases are largely associated with the excessive fat and protein
intakes that are characteristic of animal-based diets. Coupled with
sedentary lifestyles, excess meat consumption also contributes to the
epidemic of obesity.

Public policies that encourage a shift toward a more plant-based diet could
bolster individual actions in this area. These policies should include
preventing factory farms from polluting and requiring them to pay cleanup
costs when they do pollute. Without such policies, the products of factory
farms will continue to be artificially cheap, in that prices will not
reflect their impact on the environment, human health, animal welfare, or
the economic and social stability of rural communities.

Both the individual and collective actions described above would hasten the
shift toward a more sustainable agriculture, which is an important component
in the larger transition to a sustainable economy.

Sustainable agriculture is not merely a package of prescribed methods. More
important, it is a change in mindset whereby agriculture acknowledges its
dependence on a finite natural resource base--including the finite quality
of fossil fuel energy that is now a critical component of conventional
farming systems. It also recognizes that farm management problems (weeds,
insects, etc.) cannot be dealt with in isolation but must be seen as part of
a whole ecosystem whose balance must be maintained.

In this paper we have introduced some of the environmental and human health
problems inherent in industrial agriculture. In many respects,
industrial-style meat production provides a worst-case example of these
problems. It also provides an opportunity for dramatic improvements in
environmental stewardship and public health. Because meat consumption is
such a major component in the broader issues described here, its
reduction--through both individual and collective action--can have profound
effects on the health of humans, animals, and the environment.

References and Notes

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3. Heap B, Kent J, eds. Toward Sustainable Consumption: European
Perspective. London:The Royal Society, 2000. Also available:
http://www.royalsoc.ac.uk/policy/sustain/!fullsustainreport.PDF [cited 27
February 2002].

4. U.N. Food and Agriculture Organization. FAOSTAT Database. Available:
http://apps.fao.org/ [cited 10 August 2001].

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