Health Effects of MTBE Among New Jersey Garage Workers

Abstract

Methyl tertiary butyl ether (MTBE) is an oxygenated additive used in the 1993 wintertime oxyfuel program to reduce tailpipe carbon monoxide emissions. Because of complaints of acute health symptoms, particularly in the state of Alaska, this program was terminated prematurely in that state. We designed a cross-sectional cohort study of self-reported symptoms of garage workers in the state of New Jersey exposed to high and low MJBE concentration environments. Two hundred and thirty-seven participants were divided into 2 groups: 115 workers in northern New jersey sampled during the wintertime oxyfuel program, and 122 workers in southern New jersey 10 wk after the phase-out date for the program in that area. The outcome measures included a list of symptoms, of which some were felt to be attributable to MTBE exposure. Participants were asked to indicate the frequency of those symptoms they had experienced over the last 30 days. In addition, workers were given identical preshilt and postshift questionnaires and asked to rank any discomfort they were experiencing at that time from a list of symptoms. In comparing all garage workers in northern New Jersey (high exposure) to those in southern New Jersey (low exposure), no differences were found in the reporting of symptom frequency over the last 30 days. In the pre-lpostshift questionnaire analysis, both groups felt significantly worse by the end of the work day, but there was no difference between the groups across the work shift. In comparing fuelers who pump gasoline more than 5 h/day, again no differences were found in the reporting of symptom frequency over the last 30 days. In the pre-lpostshift analysis, however, the northern group reported a significantly increased number of symptoms, but again no difference was found between the groups across the workshift. Because the fuelers in the north were on average 15 yr older than those in the south, this same analysis was repeated with fuelers in the north and age-, sex-, and education-matched controls in the south. In this analysis, no group differences in symptom reporting were seen. In summary, no untoward health effects clearly attributable to MTBE exposure could be demonstrated in this cohort of healthy garage workers.