Certain environmental exposures have been implicated in pregnancy loss and infertility. The potential for environmental and occupational exposures to chemicals and pollutants to adversely affect reproduction is not surprising since these chemicals are thought to be factors in human disease.
The reproductive system of both males and females is sensitive to radiation causing temporary or permanent sterility, although a conventional Chest X-Ray or even a CT scan of the abdomen and pelvis is not sufficient to cause harm except potentially during early pregnancy. Ionizing radiation though controversial, may also affect reproduction as flight attendants and airline pilots have been reported to have a higher incidence of early miscarriage. Risks are most likely dose and duration dependent as isolated air travel does not increase the risk for reproductive problems. Similarly there is no evidence that exposure to electrical and magnetic fields are associated with adverse reproductive outcome.
Prolonged exposure to pesticides, heavy metals and organic solvents has been associated with sterility and pregnancy loss. Sperm counts are lower in men who have prolonged exposure to pesticides. Lower implantation rates have also been reported in women whose partners worked in occupations with high levels of organic solvents. Welders have been found to have lower sperm counts presumably due to heavy metal toxicity caused by lead and mercury.
Other chemicals such as phthalates have also been linked to infertility. Phthalates are substances added to plastics to increase their flexibility, transparency, durability and longevity. They are used to soften polyvinyl chloride and are responsible for that ‘new car’ smell. Phthalates may be found in glues, cosmetics, certain shampoos and other personal care products such as colognes, perfumes, deodorants and hand lotions. These chemicals may affect hormone production and have been associated with birth defects, low sperm counts and DNA damage in sperm. To reduce exposure to phthalates choose food containing plastic bottles with the recycling codes 1,2 or 5 as recycling codes 3 and 7 are more likely to contain phthalates and bisophenol A, another compound which may adversely affect fertility.