Study objective: To report the occurrence of persistent respiratory disorders, including irritant-induced asthma, among adults living and working near an environmental spill of the pesticide, metam sodium, after the derailment of a tank car.
Design: Retrospective clinical case series.
Setting: California communities situated within one-half mile of the Sacramento River, from Mt. Shasta City to Shasta Lake.
Patients: 197 adults referred to a university occupational/environmental health clinic or to a private occupational/environmental health practitioner for evaluation of health problems potentially related to the spill.
Measurements and results: History, physical examination, review of medical records, spirometry, and methacholine challenge testing revealed 20 cases of persistent irritant-induced asthma and 10 cases of persistent exacerbation of asthma.
Conclusions: This is the first reported series of cases of persistent irritant-induced asthma involving both community residents and occupationally exposed individuals.