Until recently, endosulfan was one of the most widely used pesticides  Some others -- toxaphene, dieldrin, and chlordane -- were banned or restricted in many countries in the 1980s but linger in the environment  All four have a weak effect individually in increasing estrogen levels in women  Scientists have found, however, that their potential to cause health hazards increases dramatically when the chemicals are combined  For example, a mixture of endosulfan and dieldrin had 160 to 1, 600 times more estrogen-boosting potency than either chemical did individually
Increased estrogen is associated with an increased cancer risk in women
Any two pesticides in combination pose greater health risks than do the same pesticides uncombined.