Reproductive maturation and senescence in the female brown bear

Environmental toxins, including exposure to lead, pesticides, and other chemicals, unquestionably affect fertility in men and women. Researchers have documented many examples, the strongest cases involving industrial and occupational exposures. These usually involve small numbers of people exposed to high levels of contamination. Links between infertility and everyday low-level exposure to toxins have been harder to document, but people are regularly exposed to toxins from pesticides (crop dusting), household products (baby bottles, children’s toys, cleaners, cosmetics), and industrial production (including smoke). One study found that infertile women were 27 times more likely to have handled herbicides in the...