Cattle show that ranchers have reason to worry.
Bissett W Jr, R Smith, LG Adams, R Field, W Moyer, T Phillips, HM Scott and JA Thompson. 2008. Geostatistical analysis of biomarkers of genotoxicity in cattle, Bos taurus and Bos taurus x Bos indicus, sentinels near industrial facilities. Ecotoxicology online September 1.
Cattle grazing near two massive industries in Calhoun, Texas, have DNA damage and are likely at an increased risk of developing cancer. This study was spurred by area residents and ranchers who asked scientists to study the area because they were concerned about their own health and safety. The results from cattle justify their concerns. In 2002, when this study was performed, two industries - an aluminum smelting facility and a plastics production facility - released over 600,000 kg of 43 different toxic chemicals into the local environment. Many of these chemicals cause cancer, neurotoxicity and endocrine disruption. The authors used cattle as sentinels. They collected blood samples from 21 cattle herds and examined the blood using a lab assay that detects DNA damage. The DNA damage was higher in cattle that grazed closest to the industries. The results validate the health concerns raised by area residents and ranchers, and now a human study is warranted.