...: Repetto & Baliga, 1996; Whalen, 2002; and Women's Health Initiative Observational Study, 2009) show that exposure to pesticides â particularly long term - can damage the human immune system by reducing the number of white blood cells and disease-fighting lymphocytes. Long-term health impacts can include cancer, infertility, miscarriage, male sterility, birth defects, and effects on the nervous ...