Indoor NO2 air pollution and lung function of professional cooks

M.A Arbex,A.L.F Braga,W.R Melchert,P.H.N Saldiva,A Zanobetti,A.A Cardoso,L.A.A Pereira,L.C Martins,R.F Arbex,F Negrini

doi:10.1590/s0100-879x2007000400011

Abstract

Studies of cooking-generated NO2 effects are rare in occupational epidemiology. In the present study, we evaluated the lung function of professional cooks exposed to NO2 in hospital kitchens. We performed spirometry in 37 cooks working in four hospital kitchens and estimated the predicted FVC, FEV1 and FEF(25-75), based on age, sex, race, weight, and height, according to Knudson standards. NO2 measurements were obtained for 4 consecutive days during 4 different periods at 20-day intervals in each kitchen. Measurements were performed inside and outside the kitchens, simultaneously using Palm diffusion tubes. A time/exposure indicator was defined as representative of the cumulative exposure of each cook. No statistically significant effect of NO2 exposure on FVC was found. Each year of work as a cook corresponded to a decrease in predicted FEV1 of 2.5% (P = 0.046) for the group as a whole. When smoking status and asthma were included in the analysis the effect of time/exposure decreased about 10% and lost statistical significance. On predicted FEF(25-75), a decrease of 3.5% (P = 0.035) was observed for the same group and the inclusion of controllers for smoking status and asthma did not affect the effects of time/exposure on pulmonary function parameter. After a 10-year period of work as cooks the participants of the study may present decreases in both predicted FEV1 and FEF(25-75) that can reach 20 and 30%, respectively. The present study showed small but statistically significant adverse effects of gas stove exposure on the lung function of professional cooks.

Highlights

Nitrogen dioxide (NO2) is an air pollutant which is present in both outdoor and indoor environments
NO2 is generated in outdoor environments mainly by vehicles, fossil fuel-burning power plants and industrial boilers, while indoor NO2 concentrations are affected by outdoor levels, indoor appliances such as gas stoves and kerosene heaters, cigarette smoke, and ventilation of both combustion appliances and indoor environment [1]
Changes in lung function of cooks induced by gas stove exposure have been under-explored

Summary

Introduction

Nitrogen dioxide (NO2) is an air pollutant which is present in both outdoor and indoor environments. NO2 is generated in outdoor environments mainly by vehicles, fossil fuel-burning power plants and industrial boilers, while indoor NO2 concentrations are affected by outdoor levels, indoor appliances such as gas stoves and kerosene heaters, cigarette smoke, and ventilation of both combustion appliances and indoor environment [1]. NO2 is a deep lung irritant because of its limited solubility and high oxidative potential. Exposures to high concentrations may promote severe acute lung damages and, in some cases, even death [2]. The elderly and the ill are the segments of the population more affected by NO2 exposure because of the long periods of time spent indoors [3]. Gas stoves are among the major contributors to indoor NO2 exposure. Studies conducted in New York [4] and London [5] showed that NO2 concentrations in the kitchens of homes with gas stoves (49.1 and 72.3 ppb, respectively) were higher than in the kitchens with electric stoves (8.3 and 9.5 ppb, respectively)

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