Contaminants and Disease

Emerging contaminants are being shown to have biological effects.  Many contaminants are endocrine modulators working through hormone receptors. Low level effects of legacy contaminants include endocrine disruption and immune suppression in fish.  Many of these chemicals (hormones and pharmaceuticals) are produced to have biological effects and hence may have effects on nontarget organisms at very low (ppb-ppt) levels. Other estrogen mimicking chemicals are most likely complex mixtures from both agricultural sources, such as animal wastes, pesticides and herbicides, and human sources from wastewater treatment plant effluent and other sewage discharges.