Exposure–response relationships between lifetime exposure to residential coal smoke and respiratory symptoms and illnesses in Chinese children

Abstract

Data collected in a large epidemiologic study were analyzed to examine respiratory health effects of residential coal use in 7058 school children living in the four Chinese cities of Chongqing, Guangzhou, Lanzhou, and Wuhan. A Scenario Evaluation Approach was used to develop two exposure variables, heating coal smoke and cooking coal smoke. Estimated lifetime exposures to heating coal smoke and cooking coal smoke were both classified into fourlevel ordinal scales, as follows: no reported exposure (control); lightly exposed; moderately exposed; and heavily exposed. Zero-one dummy variables were constructed for each exposure level other than the control level (total six variables). These variables were entered into the analytical model. We tested for exposure-response relationships using logistic regression models, while controlling for other relevant covariates, including an indicator variable of ambient air pollution levels. We observed monotonic and positive exposure-response relationships of exposure to heating coal smoke with modeled odds ratios (ORs) of phlegm, cough with phlegm, and bronchitis. Other health outcomes were not associated with such exposure in a monotonic exposureresponse pattern. However, ORs for cough, wheeze, and asthma were all higher in the exposed groups than in the control group. We observed no consistent associations between cooking coal smoke and the examined health outcomes. We conclude that exposure to heating coal smoke could have adverse effects on children's respiratory symptoms and illnesses in these four Chinese cities.

Household Air Pollution from Coal and Biomass Fuels in China: Measurements, Health Impacts, and Interventions

“…When lifetime exposures to coal smoke from heating were classified according to four ordinal levels (no, light, moderate, and heavy exposure), monotonic and positive exposure–response relationships were observed for OR estimates of phlegm, cough with phlegm, and bronchitis. In addition, OR estimates for cough, wheeze, and asthma were all > 1 in the exposed groups relative to the no-exposure group (Qian et al 2004). …”

Navajo Coal Combustion and Respiratory Health Near Shiprock, New Mexico

“…Of the seven respiratory conditions/diseases analyzed in the hospital records in the present study, cough, wheeze, and asthma were all significantly associated with indoor coal combustion in a previous epidemiological investigation of children in China [18]. Another report found that susceptibility to bronchitis was significantly associated with ambient PM 2.5 and polycyclic aromatic hydrocarbons (PAHs) among children in a former coal mining area in the Czech Republic with numerous large coal-fired power plants [18].…”

“…Another report found that susceptibility to bronchitis was significantly associated with ambient PM 2.5 and polycyclic aromatic hydrocarbons (PAHs) among children in a former coal mining area in the Czech Republic with numerous large coal-fired power plants [18]. Interestingly, von Mutius et al [19] noted a protective effect of in-home coal burning for children at risk of developing hay fever or other immunoglobulin E antibody-mediated allergies in southern Germany.…”

Polycycl. Aromatic Hydrocarbon Exposure of Children in Typical Household Coal Combustion Environments: Seasonal Variations, Sources, and Carcinogenic Risks

“…This means that children will inhale more pollutants indoors, which seriously affects their health and overall performance [ 9 , 10 ]. In recent years, much work has focused on the risk of cancer in children exposed to PAHs as well as the time–spatial distribution of pollutants [ 11 , 12 ] and exposure–response relationship between air pollution levels and mortality/morbidity [ 13 , 14 , 15 ]. The exposure pathway of PM may have a potential impact on children [ 16 ].…”