To truly assess the risks posed by a ubiquitous group of chemicals found in everything from vinyl shower curtains to bug spray, researchers need to study their cumulative impact on human health, declares a new report from the National Research Council, a group that advises the government on science and health policy. The chemicals, called phthalates, are used to make plastic products soft and flexible, and are also found in cosmetics, personal-care products, and even pharmaceuticals. In rodent studies exposure to phthalates has been shown to interfere with the development of the male reproductive system, causing
infertility, reduced sperm production, undescended testes, penile birth defects and other reproductive-tract malformations [Science News].
Traditionally, health agencies have studied the risk of each chemical individually, but experts say such a process doesn't accurately reflect human exposure.
"It is extremely important to conduct cumulative risk assessments to protect public health," said [phthalate researcher] Dr. ...
