Air pollution is a traveling, insidious health problem. In other words, air pollution created in Michigan affects those in Canada, and pollution that enters the air in Asia affects people living on the California coast. Air pollution is a worldwide problem that must be addressed with worldwide solutions. The Commission on Pollution and Health1 is an initiative of The Lancet, the Global Alliance on Health and Pollution and the Icahn School of Medicine at Mount Sinai. A report from the Commission found:2,3
"[T]he largest contributor to pollution-related deaths is air pollution ... linked to an estimated 6.5 million deaths in 2015 as a result of diseases such as heart disease, stroke, lung cancer and COPD [chronic obstructive pulmonary disease]."
Fine particulate matter (PM 2.5) is the most studied type of air pollution and refers to dust, dirt, soot, smoke or particles that are smaller than 2.5 micrometers in diameter. These particles of air pollution are so fine they are able to enter your system through your lung tissue and trigger chronic inflammation, which in turn increases your risk of health problems. A recent study has found exposure to these fine particles may be a factor affecting the quality of men's sperm and fertility.4
Air Pollution Linked to Poor Sperm Quality
In this study, researchers evaluated the quality of sperm from nearly 6,500 men ages 15 to 49 between 2001 and 2014. The men willingly participated in a standard medical examination program in Taiwan. The quality of the semen was evaluated based on 1999 standards developed by the World Health Organization (WHO) that included concentration, motility and morphology.5 The researchers estimated the particle concentration at the participant’s home using a spatiotemporal model and satellite optical depth data.
Data was evaluated using three-month and two-year averages of exposure to particulate matter. They found a robust association between altered morphology and level of exposure to PM 2.5 particulate pollution. In fact, with every incremental increase in exposure to particulate matter, sperm morphology degraded by 1.29 percent.
This was the largest study evaluating the effect particulate pollution has on semen quality to date. The negative association between air pollution and sperm morphology was found in other studies6 done in China,7 the Czech Republic8 and Poland.9 The lead author of the featured study commented on the results, saying:10
"Particulate matter contains many toxic chemicals such as heavy metals and polycyclic aromatic hydrocarbons, which have demonstrated harm to semen quality in laboratory and animal studies."
These results are concerning as sperm morphology has a critical long-term effect on fertility and on the health of babies born to men whose sperm is affected by pollution. Research has demonstrated the health of a man's sperm11 is affected by lifestyle choices and consequently has an effect on his child.12
Next Generation's Health Affected Before Birth
The effect air pollution has on the health of your family extends to your baby before they are born. In a study from Greater London, researchers found a link between exposure to air pollution and birth defects.13 The researchers looked at air pollution and noise pollution between 2006 and 2010.14 They amassed data from just over 540,000 babies born in those years and whose mothers lived in the prescribed geographical area.
The data indicated the average exposure to pollution was 14 micrograms per cubic meter of PM 2.5-sized particulates. For every 5 microgram-per-cubic meter increase of particulates, the researchers discovered a 15 percent increase in low birth weight births.
Children born at a low birth weight are at higher risk for Type 2 diabetes, heart disease, obesity and high blood pressure as well as have a greater risk for birth defects.15 At birth, these babies are also at risk for respiratory distress syndrome, bleeding in the brain and necrotizing enterocolitis.
There are several standards for what is considered "safe" exposure to particulate matter. The U.S. Environmental Protection Agency (EPA) standard for exposure was 15 micrograms per cubic meter in 1997. In 2009, the standard was remanded by the U.S. Court of Appeals and revised in 2012 to 12 micrograms per cubic meter averaged over three years.16 The WHO standards suggest that 10 micrograms per cubic meter should be the safe limit.
However, one author of this study, Mireille B. Toledano, an epidemiologist at Imperial College London, stated there really is no safe level of pollution and went on to comment on the results of the study, saying:17
"For every 10 percent reduction in PM 2.4, we can prevent 90 babies being born with low birth weight in London. The current limits are not protecting pregnant women, and they are not protecting unborn babies."
A study performed by researchers from the Cincinnati Children's Hospital found similar results. The study, published in the journal Environmental Health,18 demonstrated increased exposure to small particulate pollution increased the risk of preterm birth. A 19 percent increased risk for preterm birth was identified, especially when pregnant women’s exposure was greatest in the third trimester.19
Another study from the University of Cincinnati found women exposed to high levels of small particulate pollution in the month before and after conception had a higher risk of delivering a baby with birth defects such as cleft lip and palate or heart abnormalities.20