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Last Edited: 3/23/2009

Population Fertility and the Environment

How might fertility be related to the environment?

As difficult as it is to make inferences about fertility from rates of childbirth in populations, it is unsurprising that little is known about the impacts of environmental pollution on human reproduction.  There is a consensus, however, that connections between environmental chemicals and human reproduction are plausible.1  Many common, persistent pollutants share properties with human sex hormones and are known to alter the body's ability to regulate these hormones.  It is also well established that both male and female embryos are vulnerable to the actions of these chemicals, and that the consequences of exposure may only become apparent when people reach adulthood, such as menstrual cycle length in women or spermatic activity in men.2, 3

Several researchers have noted that indicators of sperm production and activity in men have declined over recent decades, although the consistency of this finding is uncertain.4  These indicators, in addition to time-to-pregnancy (TTP) measures among couples seeking to conceive, do vary geographically in ways that have not yet been explained. Finally, exposures to environmentally persistent chemicals 6, 7 and acute residential exposures to air pollution8 have been associated with reproductive function in men.  Overall, these patterns can serve as reminders of our position as a species in the ecosystem and how little we know about the long-term effects of the changes we make to it.

1.    Foster W, Neal M, Han M-S, Dominguez M. Environmental contaminants and human infertility:  hypothesis or cause for concern? Journal of Toxicology and Environmental Health, Part B. 2008;11:162-176.
2.    Foster W. Fetal and early postnatal environmental contaminant exposures and reproductive effects in the female. Fertility and Sterility. 2008;89(Suppl 1):e53.
3.    Swan S. Fetal and postnatal environmental exposures and reproductive health effects in the male:  recent findings. Fertility and Sterility. 2008;89(Suppl 1):e45.
4.    Auger J, Kunstmann J, Czyglik F, Jouannet P. Decline in semen quality among fertile men in Paris during the past 20 years. New England Journal of Medicine. 1995;332(5):281-285.
5.    Joffe M. Decreased fertility in Britain compared with Finland. Lancet. 1996;347:1519-1522.
6.    Bonde J, Toft G, Rylander L, et al. Fertility and markers of male reproductive function in Inuit and European populations spanning large contrasts in blood levels of persistent organochlorines. Environmental Health Perspectives. 2008;116:269-277.
7.    Giwercman A, Rignell-Hydbom A, Toft G, et al. Reproductive hormone levels in men exposed to persistent organohalogen pollutants:  a study of Inuit and three European cohorts. Environmental Health Perspectives. 2006;114:1348-1353.
8.    Dejmek J, Selevan S, Benes I, Solansky I, Sram R. Fetal Growth and Maternal Exposure to Particulate Matter During Pregnancy. Environmental Health Perspectives. 1999;107:475-480.