Environmental and occupational pollutants exposure and infertility

Approximately 15% of the world population is impacted by infertility. Recent research has shown that environmental and occupational factors have profound effects on the population's overall health and fertility status. While cigarette smoking and its component chemicals are known toxic agents affecting the quality and quantity of oocytes, other toxic substances ubiquitous in our environment appear to have toxic effects on the reproductive system at environmentally relevant levels. Certain industrial chemicals, environmental pollutants, and radiation are known to contribute to or cause infertility. Lead poisoning, for example, has long been associated with infertility in both men and women. Chemotherapy and x-ray therapy used in cancer treatment can be extremely toxic to sperm and oocytes and can cause permanent infertility. In some countries, fertility programs recommend that men who will be undergoing chemotherapy store their sperm before treatment. Similarly, oocyte retrieval before a woman's cancer treatment and freezing the oocytes or embryos for later use, is also advised. Long soaks in the bathtub or hot tub or long hours of sitting and excessive bicycling can cause the temperature in the scrotum to increase enough to impair sperm production. A febrile illness can also lead to a significant decline in sperm motility. Considering all these elements, the influence of environmental and occupational conditions on reproductive well-being has generated a considerable amount of interest among researchers. Recent studies have aimed to clarify the association and possible mechanisms between reduced fertility and exposure to environmental and occupational contaminants. This chapter summarizes the recently published, epidemiological findings referring to the impact of environmental (air pollution, heavy metals, pesticides, endocrine disruptors and other chemicals, radiation) and occupational factors on fecundity and fertility. Daily exposure to environmental and occupational hazards has negative ramifications for fertility via several sources such as biological, physical (radiation), and toxic (chemicals, endocrine-disrupting chemicals, heavy metals). Future studies are needed to better elucidate the additional associations and potential mechanisms between these environmental chemicals and fertility outcomes in men and women.