Tulane University epidemiologist Eric Johnson is hot on the trail of environmental exposures to viruses that might cause cancer. He is slated to receive about $1 million over three years from the Centers for Disease Control and Prevention to analyze the health outcomes of people who worked in poultry slaughtering and processing plants.

In 1997 and 2003, Johnson published results of two studies of over 10,000 poultry workers who had worked in poultry plants between 1949 and 1990 in Baltimore and Missouri. Those results indicated a possible link between exposure to viruses in chicken and turkeys and later development of cancer in humans. This funding will allow Johnson and his colleagues to add poultry workers from several more states identified through a pension fund in Chicago, resulting in nearly 30,000 people to be studied.

"This is the largest study of people who have been exposed to the viruses that cause cancer in poultry," says Johnson. "It will help us determine whether the increased risks of certain cancers based on small numbers we saw in our earlier studies are real and significant."

According to Johnson, poultry workers have the highest exposure to animal cancer-causing viruses. The results of his earlier studies were published in the October 2003 issue of the journal of Occupational & Environmental Medicine 60:784-788 and the International Journal of Epidemiology 1997; 26: 1142-1150.