During 1998, the Pennsylvania Department of Health received complaints about hydrogen sulfide odors believed to be associated with mushroom-composting operations in southeastern Pennsylvania. Many residents were concerned about possible illness in students attending an elementary school near the composting operations. In response, the department conducted health surveys during the spring and autumn at the exposed school and at a nearby control school. The surveys assessed whether exposures to hydrogen sulfide were associated with excess adverse health effects by comparing health effects among students from the exposed school with those among students from the control school. School nurses were trained to complete health questionnaires for the students. The state environmental agency measured daily ambient hydrogen sulfide concentrations at both schools. No consistent association was found between exposure to low levels of hydrogen sulfide and any adverse health effects. It was concluded that the students atte nding the elementary school near the mushroom-composting operations were not exposed to any significant public health hazard.
During 1998, the Pennsylvania Department of Health received numerous complaints about odors that were noted near mushroom-composting operations in Chester County, southeastern Pennsylvania. Many residents were concerned that exposure to hydrogen sulfide in the air might cause illness in students attending a nearby elementary school. In response to these complaints, the Department of Health decided to conduct a school health survey during the spring of 1998 at an elementary school in the affected area. An elementary school from the same school district located five miles away and not affected by the composting operations also was selected for the survey for purposes of comparison. In response to requests for additional investigation, the department conducted another survey during the autumn of 1998 to determine if seasonal variations in health effects existed.
The primary purpose of the health surveys was to determine if exposure to hydrogen sulfide was associated with excess symptoms or other adverse health conditions by comparing health effects among students from the exposed school with health effects among students from the control school, The Pennsylvania Department of Environmental Protection (DEP) collaborated with the Department of Health by monitoring daily hydrogen sulfide concentrations in the air at both schools.
In collaboration with the school district, DEP developed an overall program for air monitoring at both schools, and the Department of Health made plans for conducting the health surveys. The Department of Health developed a two-page questionnaire, which included a checklist of 11 symptoms, and questions about general medical history and six diagnosed medical conditions (Figure 1). The checklist included symptoms that might be related to hydrogen sulfide exposure and an open-ended question (1). The spring survey was conducted while school was in session, from April 20 through June 5, 1998 (33 days). The autumn survey was conducted from August 31 through October 30, 1998 (42 days), also while school was in session. School nurses assisted the Department of Health by completing questionnaires for students.
Before the spring survey, Department of Health officials met with school...