The Effects of Environmental Toxins on Fertility
The global birth rate is steeply declining. While much of the 50% decrease in the number of children born per woman in the past 60 years is due to choice, an increasing number of couples—now 1 in 7-10 in North America—are having serious difficulty conceiving. Environmental toxins are a large factor when discussing the decrease of fertility. The toxins that we breathe, rub on our skin, eat, and drink have been shown to directly cause diabetes, obesity, and polycystic ovary syndrome. As if becoming pregnant wasn't difficult enough for some women, these toxins are just added risks to the fetus once conception is finally achieved. Endocrine disruption has become a leading response in men and women who are contaminated by environmental toxins. Endocrine-disrupting chemicals (EDCs) impact the endocrine system and subsequently impair the development and fertility of humans.
Bisphenol A (BPA) is one of the most commonly used environmental toxins that can negatively affect reproductive systems. While the study of BPA against fertility is considered understudied, there has been evidence that BPA can cause recurrent miscarriages, damaged DNA in sperm, disruptions in cell survival, and spontaneous abortion of cells but these associations have yet to be explored in the context of pregnancy. Thus, there is a clear need for epidemiological studies assessing BPA exposure and adverse pregnancy outcome including gestational diabetes, preeclampsia/eclampsia, and pregnancy loss.
BPA is not the only concern when it comes to pregnancy. Women drinking groundwater with tetrachloroethylene (PCE) contamination suffer over a potentially doubled risk of spontaneous abortion as well as increased risk of breast cancer. By the same token, chlorinated water has been proved to contain Disinfection By-Products (DPB) which have led to increased risk of cancer development and unfavorable reproductive outcomes. Some of the reproductive outcomes are neural tube defects, cardiovascular defects, cleft defects, as well as chromosomal abnormalities. In addition, drinking chlorinated water increases the risk of stillbirth, small head circumference, and small body length.
Chemicals found in pesticides have also been shown to create reproductive issues in men and women. Hexachlorocyclohexane, polychlorinated biphenyls (PCBs), and dichlorodiphenyltrichloroethane (DDT) are common toxins mainly found in pesticides that are sprayed on fruits and vegetables and can be ingested by animals and fish that we also ingest. Considering that the elements, such as wind and rain, can move the pesticides from their intended areas, it is ultimately possible that groundwater and grazing land are contaminated unintentionally during pesticide application. Women with the highest levels of PCBs have a serious 50% decrease in their ability to get pregnant and if they become pregnant are much more likely to miscarry. In a study conducted in Canada on female farmers in Ontario, data showed that fertility levels decreased in proportion to pesticide use.
Source: Jonathan Kemper on Unsplash
Water is not the only source of endocrine-disrupting toxins. The air we breathe is heavily contaminated as well. Smoking decreases fertility rates in men and women due to the heavy metal and chemical toxins that cigarettes are laced with. Smoking also causes higher rates of ectopic pregnancies and spontaneous abortions, stillbirths, and infant mortality. Cigarette smoking also decreases male fertility, resulting in decreased sperm density, total sperm count, and the number of motile sperm. Smoking is not the only source of air pollution, motor vehicle exhaust fumes are associated with fertility rates in men and women. Men residing in an industrial town suffered a significant reduction in sperm motility and morphology and higher levels of sperm with abnormal chromatin when compared with those living in a rural district with little air pollution; and women who are exposed suffer increased rates of miscarriage, and higher infertility rates.
There has been a steady decrease in birth rate as our country has developed, and science has given people access to longer lifespans. Over the past 60 years, the average birth rate has dropped from 4.5-7 children per family to 2 children per family. The biggest differences between then and now were shorter lifespans and undereducated women. As countries become more developed education, healthcare, and jobs become more accessible to everyone. As women receive higher education and enter the workforce, they often delay childbirth until later in life or decide against it. This creates a larger gap between the generations to come and the current workforce. Without constant repopulation, the workforce could eventually be in danger of declining significantly. There are theories that we can save the workforce by attempting to save fertility rates, or a more controversial approach is to attempt to immigrate workforce-aged migrants. Neither of which is a permanent solution.
The environmental toxins that we face every day, such as PCBs, BPA, DDT and are taking a toll on our reproductive abilities.
Fertility rates have seen a steady decline over the last 60 years, causing concern for the workforce.
There is no solution at this time for the damage that environmental toxins are causing.