A pilot study of indoor exposure to pollutants from kerosene space heaters

摘要

Kerosene space heaters are used in about 10% of French households. Because they are unvented devices, pollutants build up in the rooms during their use. In a recent laboratory study, we have shown that only wick type kerosene heaters significantly emit CO, specially when soot accumulates on the heater, but that with all heaters, high NO2 and CO2 concentrations are to be expected, exceeding the recommended values for indoor air. The aim of this work was to confirm that the concentrations of pollutants in households using a kerosene heater correspond to the estimates from laboratory emission factors measurements, and to evaluate the exposure of people to these emissions. This work was also intended to prepare the analytical protocols for a future full scale study investigating the link between kerosene heater use and respiratory diseases. Measurements were performed in 6 dwellings, during winter 2010-2011, using CO, CO2, T, RH real-time probes, and passive sampling techniques for NOx, VOCs, and aldehydes. The characteristics of the dwellings and the activities possibly influencing the air quality during the week-long measurements were documented with questionnaires. Average daily duration of use of the heaters ranged from 2 to over 10 hours. CO2 concentration patterns and levels are a clear tracer of kerosene heater use. Daily average CO2 concentrations, up to 1700 ppb, are proportional to the duration of use, and so are the weekly average NO2 concentrations, ranging from 30 to 580 ppb. Only in the houses with wick-type heaters were the CO concentrations non zero, with an average 1-h maximum of 12 ppm. VOCs and aldehydes concentrations were low, with formaldehyde for instance not exceeding 12 ppb 11-week average), in accordance with laboratory results. These results agree with the estimates from laboratory emission factors measurements, and confirm that the use of kerosene heaters leads to poor indoor air quality and increases the exposure to respiratory irritants.