Case reports: Epidemic eye and upper respiratory irritation in poultry processing plants

Case studies conducted at six poultry processing plants by the National Institute for Occupational Safety and Health (NIOSH), the Occupational Safety and Health Administration (OSHA), the U.S. Department of Agriculture (USD A), and state health departments revealed that processors and inspectors experienced acute eye and upper respiratory irritation associated with their work. The most frequently reported symptoms were burning, watery eyes; sneezing; stuffy, runny nose; and cough. Other symptoms included blurred vision, light sensitivity, sore throat, headache, and nausea. Occasionally symptoms became so severe that inspectors and workers refused to continue working. Although prevalence data were often not collected, greater than 90 percent of the workers reported having symptoms in the hanging, evisceration, and inspection areas at one plant. These outbreaks were all associated with problems or changes in the plants’ water chlorination and super-chlorination processes. The inception of complaints at three of the plants was closely associated with the switch to chloramina- tion as a method of disinfection by the local water supply companies. Chloramination has been reported to produce and release the gas trichloramine, a mucous membrane irritant. Investigators collected area and personal breathing zone air samples at the plants to estimate worker exposures to chlorine and ammonia, but the concentrations of these gases were always low, with a maximum of 0.18 ppm for chlorine and a maximum of 3 ppm for ammonia. These concentrations are well below OSHA, NIOSH, and American Conference of Governmental Industrial Hygienists exposure criteria; however, these long-term samples were not capable of detecting short-term peaks of the gases. There is currently no method available for measuring trichloramine in air. Chlorine levels were also measured in water and at times were found to range well above the 20 ppm concentration required by the USDA for sanitizing the evisceration machines. The companies tried various methods to resolve the complaints, including constructing a new water supply system, strict control of super-chlorination of water on processing machines, and ventilation changes. These procedures have served to largely control or eliminate complaints.