Investigation of possible health effects of community exposure to fermenting wood chips.

We conducted a case-control study of emergency room (ER) patients to evaluate whether asthma is caused by living near a wood-chip fueled power plant that released wood-chip fermentation products. Only eight (29 per cent) of 28 asthma patients seen in the ER during an 11-week period lived within 1.5 miles of the plant compared with 18 (34 per cent) of 54 control patients matched for severity of diagnosis and seen during the same period (Mantel-Haenszel odds ratio controlling for age = 0.96).