Wan-Hui Ren

Association between long-term air pollution and increased blood pressure and hypertension in China.

Several studies have investigated the short-term effects of ambient air pollutants in the development of high blood pressure and hypertension. However, little information exists regarding the health effects of long-term exposure. To investigate the association between residential long-term exposure to air pollution and blood pressure and hypertension, we studied 24 845 Chinese adults in 11 districts of 3 northeastern cities from 2009 to 2010. Three-year average concentration of particles with an aerodynamic diameter ⩽10 µm (PM10), sulfur dioxide (SO2), nitrogen dioxides (NO2), and ozone (O3) were calculated from monitoring stations in the 11 districts. We used generalized additive models and 2-level logistic regressions models to examine the health effects. The results showed that the odds ratio for hypertension increased by 1.12 (95% confidence interval [CI], 1.08–1.16) per 19 &mgr;g/m3 increase in PM10, 1.11 (95% CI, 1.04–1.18) per 20 &mgr;g/m3 increase in SO2, and 1.13 (95% CI, 1.06–1.20) per 22 &mgr;g/m3 increase in O3. The estimated increases in mean systolic and diastolic blood pressure were 0.87 mm Hg (95% CI, 0.48–1.27) and 0.32 mm Hg (95% CI, 0.08–0.56) per 19 &mgr;g/m3 interquartile increase in PM10, 0.80 mm Hg (95% CI, 0.46–1.14) and 0.31 mm Hg (95% CI, 0.10–0.51) per 20 &mgr;g/m3 interquartile increase in SO2, and 0.73 mm Hg (95% CI, 0.35–1.11) and 0.37 mm Hg (95% CI, 0.14–0.61) per 22 &mgr;g/m3 interquartile increase in O3. These associations were only statistically significant in men. In conclusion, long-term exposure to PM10, SO2, and O3 was associated with increased arterial blood pressure and hypertension in the study population.

Breastfeeding as a modifier of the respiratory effects of air pollution in children.

Background: Breastfeeding and air pollution are both important factors for respiratory symptoms and asthma in children. Few studies have examined possible interaction between them on respiratory outcomes. Methods: We studied 31,049 Chinese children, ages 2–14 years old, from 25 elementary schools and 50 kindergartens in the Seven Northeastern Cities during 2008–2009. Parents or guardians completed questionnaires about the children’s histories of respiratory conditions, risk factors, and feeding methods. Three-year average concentrations of particles with an aerodynamic diameter ⩽10 µm, sulfur dioxide, nitrogen dioxides, and ozone were calculated from monitoring stations in 25 study districts. We used two-level logistic regressions to examine the effects of exposure, controlling for covariates. Results: Association of air pollution with childhood respiratory conditions was modified by breastfeeding. Compared with children who had been breastfed, those who were not exhibited consistently stronger effects of air pollution. Among non-breastfed children, odds ratios (ORs) per 10 µg/m3 increase in nitrogen dioxide were 1.40 (95% confidence interval = 1.19–1.64) for cough, 1.41 (1.16–1.71) for phlegm, 1.17 (1.00–1.36) for current wheeze, and 1.25 (1.07–1.46) for doctor-diagnosed asthma. For breastfed children, the ORs were 1.25 (1.09–1.43) for cough, 1.15 (0.99–1.34) for phlegm, 0.97 (0.87–1.08) for current wheeze, and 1.17 (1.05–1.32) for doctor-diagnosed asthma. Breastfeeding was more protective among younger children. Breastfeeding was also associated with reduced effects of passive smoke exposure in children. Conclusion: Breastfeeding is associated with smaller associations between air pollution and respiratory conditions in children, suggesting that breastfeeding reduces susceptibility to the respiratory effects of pollutants.

Air pollution associated hypertension and increased blood pressure may be reduced by breastfeeding in Chinese children: The Seven Northeastern Cities Chinese Children's Study

BACKGROUND Little is known about the association between air pollution and hypertension among children, and no studies report whether breastfeeding modifies this association in children. METHODS Nine thousand three hundred fifty-four Chinese children, ages 5-17 years old, from 24 elementary schools and 24 middle schools in the Seven Northeastern Cities during 2012-2013 were evaluated. The weight, height, and BP were measured. Four-year average concentrations of particles with an aerodynamic diameter of ≤10 μm (PM10), sulfur dioxide (SO2), nitrogen dioxides (NO2), ozone (O3), and carbon monoxide (CO) were calculated from monitoring stations. Two-level regression analysis was used to examine the effects, controlling for covariates. RESULTS The results showed that associations existed between hypertension and pollutants. The odds ratios for hypertension ranged from 1.12 per 46.3 μg/m3 increase for O3 (95% confidence interval [CI], 1.10-1.13) to 1.68 per 30.6 μg/m3 increase for PM10 (95% CI, 1.53-1.86). The increases in mean diastolic BP ranged from 0.58 mm Hg per 46.3 μg/m3 increase for O3 (95% CI, 0.52-0.63 mm Hg) to 2.89 mm Hg per 563.4 μg/m3 increase for CO (95% CI: 2.53-3.24 mm Hg). The increase in systolic BP ranged from 0.50 mm Hg per 46.3 μg/m3 increase for O3 (95% CI: 0.43-0.57 mm Hg) to 2.10 mm Hg per 30.6 μg/m3 increase for PM10 (95% CI, 1.73-2.47 mm Hg). Compared with children who had been breastfed, non-breastfed children exhibited consistently stronger effects. CONCLUSION Study findings indicate that high levels of PM10, SO2, NO2, O3, and CO are associated with increased arterial BP and hypertension among the children. Breastfeeding may reduce the risk.

Interactions Between Air Pollution and Obesity on Blood Pressure and Hypertension in Chinese Children.

Background: Little information exists regarding the effect of interaction of obesity and long-term air pollution exposure on children’s blood pressure and hypertension in areas with high levels of air pollution. The aim of this study is to assess effect modification by obesity on the association between exposure and blood pressure in Chinese children. Methods: We studied 9,354 Chinese children, ages 5–17 years old, from 24 elementary schools and 24 middle schools in the Seven Northeastern Cities during 2012–2013. Four-year average concentrations of particles with an aerodynamic diameter ⩽10 µm (PM10), sulfur dioxide, nitrogen dioxides, and ozone (O3) were measured at the monitoring stations in the 24 districts. We used generalized additive models and two-level logistic regression models to examine the health effects. Results: Consistent interactions were found between exposure and obesity on blood pressure and hypertension. The association between exposure and hypertension was consistently larger for overweight/obese children than for children with normal-weight, with odds ratios for hypertension ranging from 1.16 per 46.3&mgr;g/m3 for O3 (95% confidence interval [CI] = 1.12, 1.20) to 2.91 per 30.6&mgr;g/m3 for PM10 (95% CI = 2.32, 3.64), and estimated increases in mean systolic and diastolic blood pressure ranging from 0.57 mmHg (95% CI = 0.36, 0.78) and 0.63 mmHg (95% CI = 0.46, 0.81) per 46.3 &mgr;g/m3 for O3 to 4.04 mmHg (95% CI = 3.00, 5.09) and 2.02 mmHg (95% CI = 1.14, 2.89) per 23.4 &mgr;g/m3 for sulfur dioxide. Conclusions: Obesity amplifies the association of long-term air pollution exposure with blood pressure and hypertension in Chinese children.

Gender-specific differences of interaction between obesity and air pollution on stroke and cardiovascular diseases in Chinese adults from a high pollution range area: A large population based cross sectional study

BACKGROUND Little information exists regarding the interaction effects of obesity with long-term air pollution exposure on cardiovascular diseases (CVDs) and stroke in areas of high pollution. The aim of the present study is to examine whether obesity modifies CVD-related associations among people living in an industrial province of northeast China. METHODS We studied 24,845 Chinese adults, aged 18 to 74 years old, from three Northeastern Chinese cities in 2009 utilizing a cross-sectional study design. Body weight and height were measured by trained observers. Overweight and obesity were defined as a body mass index (BMI) between 25-29.9 and ≥30 kg/m(2), respectively. Prevalence rate and related risk factors of cardiovascular and cerebrovascular diseases were investigated by a questionnaire. Three-year (2006-2008) average concentrations of particulate matter (PM10), sulfur dioxide (SO2), nitrogen dioxides (NO2), and ozone (O3) were measured by fixed monitoring stations. All the participants lived within 1 km of air monitoring sites. Two-level logistic regression (personal level and district-specific pollutant level) was used to examine these effects, controlling for covariates. RESULTS We observed significant interactions between exposure and obesity on CVDs and stroke. The associations between annual pollutant concentrations and CVDs and stroke were strongest in obese subjects (OR 1.15-1.47 for stroke, 1.33-1.59 for CVDs), less strong in overweight subjects (OR 1.22-1.35 for stroke, 1.07-1.13 for CVDs), and weakest in normal weight subjects (OR ranged from 0.98-1.01 for stroke, 0.93-1.15 for CVDs). When stratified by gender, these interactions were significant only in women. CONCLUSIONS Study findings indicate that being overweight and obese may enhance the effects of air pollution on the prevalence of CVDs and stroke in Northeastern metropolitan China. Further studies will be needed to investigate the temporality of BMI relative to exposure and onset of disease.

Ambient air pollution and the prevalence of obesity in chinese children: The seven northeastern cities study

The association between air pollution and the prevalence of overweight and obesity is evaluated.

Home Renovation, Family History of Atopy, and Respiratory Symptoms and Asthma Among Children Living in China

OBJECTIVES To investigate the association of indoor air pollution with the respiratory health of children, we evaluated the associations of childrens respiratory symptoms with asthma and recent home renovation. METHODS We conducted a cross-sectional survey in a school recruitment sample of 31,049 children aged 2 to 14 years in 25 districts of 7 cities of northeast China in 2008-2009. The childrens parents completed standardized questionnaires characterizing the childrens histories of respiratory symptoms and illness, recent home renovation information, and other associated risk factors. RESULTS The effects of home renovation in the past 2 years were significantly associated with cough, phlegm, current wheeze, doctor-diagnosed asthma, and current asthma. The associations we computed when combining the status of home renovation and family history of atopy were higher than were those predicted from the combination of the separate effects. However, the interactions between home renovation and family history of atopy on a multiplicative scale were not statistically significant (P>.05). CONCLUSIONS Home renovation is associated with increases in the prevalence of respiratory symptoms and asthma in children. The effects of different renovation materials on child respiratory health should be studied further.

Residential characteristics and household risk factors and respiratory diseases in Chinese women: the Seven Northeast Cities (SNEC) study.

BACKGROUND Few studies have assessed the impact of residential home characteristics and home environmental risk factors on respiratory diseases in Chinese women. Therefore, this study sought to determine the association between residential home features, domestic pets, home renovation and other indoor environmental risk factors with respiratory health outcomes of Chinese women. METHODS This cross-sectional study included a study sample of 30,780 Chinese women aged 23 to 49 from 25 districts of seven cities in Liaoning Province, Northeast China. Information on respiratory health, residential characteristics, and indoor air pollution sources was obtained by a standard questionnaire from the American Thoracic Society. Multivariable logistic regression was used to estimate prevalence odds ratios (POR) and 95% confidence interval (95%CI). RESULTS The odds of respiratory diseases were higher for those who lived near the main road, or near ambient air pollution sources. Pet-keeping was associated with increased odds of chronic bronchitis (POR=1.40; 95%CI: 1.09-1.81) and doctor-diagnosed asthma (POR=2.07; 95%CI: 1.18-3.64). Additionally, humidifier use was associated with increased odds of chronic bronchitis (POR=1.44; 95%CI: 1.07-1.94). Home renovation in recent 2 years was associated with increased likelihood of allergic rhinitis (POR=1.39; 95%CI 1.17-1.64). CONCLUSION Home renovation and residential home environmental risk factors were associated with an increased likelihood of respiratory morbidity among Chinese women.