Zilong Zhang

Satellite-based estimates of long-term exposure to fine particulate matter are associated with C-reactive protein in 30 034 Taiwanese adults

Abstract Background Particulate matter (PM) air pollution is associated with the risk of cardiovascular morbidity and mortality. However, the biological mechanism underlying the associations remains unclear. Atherosclerosis, the underlying pathology of cardiovascular disease, is a chronic inflammatory process. We therefore investigated the association of long-term exposure to fine PM (PM2.5) with C-reactive protein (CRP), a sensitive marker of systemic inflammation, in a large Taiwanese population. Methods Participants were from a large cohort who participated in a standard medical examination programme with measurements of high-sensitivity CRP between 2007 and 2014. We used a spatiotemporal model to estimate 2-year average PM2.5 exposure at each participant’s address, based on satellite-derived aerosol optical depth data. General regression models were used for baseline data analysis and mixed-effects linear regression models were used for repeated data analysis to investigate the associations between PM2.5 exposure and CRP, adjusting for a wide range of potential confounders. Results In this population of 30u2009034 participants with 39u2009096 measurements, every 5u2009μg/m3 PM2.5 increment was associated with a 1.31% increase in CRP [95% confidence interval (CI): 1.00%, 1.63%) after adjusting for confounders. For those participants with repeated CRP measurements, no significant changes were observed between the first and last measurements (0.88u2009mg/l vs 0.89u2009mg/l, Pu2009=u20090.337). The PM2.5 concentrations remained stable over time between 2007 and 2014. Conclusions Long-term exposure to PM2.5 is associated with increased level of systemic inflammation, supporting the biological link between PM2.5 air pollution and deteriorating cardiovascular health. Air pollution reduction should be an important strategy to prevent cardiovascular disease.

Frequent use of household cleaning products is associated with rhinitis in Chinese children

BACKGROUNDnDespite the popular use of household cleaning products worldwide, there is no published study investigating the health effects of these products on rhinitis in children.nnnOBJECTIVEnWe sought to investigate the household use of cleaning products and rhinitis patterns in Chinese children.nnnMETHODSnA total of 2299 children were recruited from 21 primary schools with wide geographic coverage in Hong Kong. Self-administered questionnaires were completed by parents/guardians to collect detailed information on respiratory symptoms and household use of 14 types of chemical cleaning products, as well as clean water. Students were categorized into 4 mutually exclusive rhinitis patterns (never, occasional, frequent, and persistent). The total chemical burden (TCB) score was used as the exposure indicator by calculating the total time of exposure to the 14 cleaning products. Multinomial logistic regression was used to assess the relationship between rhinitis patterns and the use of household cleaning products.nnnRESULTSnEvery 10-unit increment of TCB score was associated with an increase in the odds of occasional (odds ratio [OR], 1.21; 95% CI, 1.05-1.41), frequent (OR, 1.36; 95% CI, 1.13-1.60), and persistent (OR, 1.21; 95% CI, 1.01-1.56) rhinitis after adjustment for a wide range of potential confounders. Compared with the children within the lowest tertile of TCB scores, the adjusted ORs of occasional, frequent, and persistent rhinitis in children within the highest tertile were 1.29 (95% CI, 1.01-1.65), 1.97 (95% CI, 1.40-2.76), and 1.67 (95% CI, 1.10-2.54), respectively.nnnCONCLUSIONnFrequent use of chemical cleaning products at home is associated with an increase in the odds of rhinitis in Chinese primary school children.

Particulate matter air pollution, physical activity and systemic inflammation in Taiwanese adults

BACKGROUNDnThe protective effects of physical activity (PA) against chronic disease can be partially ascribed to its anti-inflammatory effects. On the other hand, long-term exposure to particulate matter with an aerodynamic diameter less than 2.5μm (PM2.5) may induce systemic inflammation.nnnOBJECTIVEnTo investigate the joint effects of habitual PA and long-term exposure to PM2.5 on systemic inflammation in a large cohort of Taiwanese adults.nnnMETHODSnWe studied 359,067 adult participants from a cohort consisting of Taiwanese residents who participated in a standard medical examination program from 2001 to 2014. Peripheral white blood cell (WBC) and differential counts were measured as indicators of systemic inflammation. Two-year average concentration of PM2.5 was estimated at each participants address using a satellite-based spatio-temporal model. Habitual PA level was assessed by questionnaire (inactive, low, moderate and high). Mixed-effects linear regression model was used to examine the associations of WBC counts with PM2.5 and PA.nnnRESULTSnCompared with inactive participants, those with low, moderate or high PA levels had 0.36% [95% confidence interval (CI): 0.31%, 0.41%], 0.70% (95%CI: 0.65%, 0.76%) and 1.16% (95%CI: 1.11%, 1.22%) lower WBC counts, respectively, after adjusting for PM2.5 exposure and a wide range of confounders. Long-term PM2.5 exposure was associated with increased WBC counts at all PA levels. Analyses for differential counts generated similar results. No significant interaction was observed between PA and PM2.5 exposure (P for interaction=0.59).nnnCONCLUSIONSnHabitual PA was associated with statistically significant lower markers of systemic inflammation across different levels of PM2.5. Effects of PA and PM2.5 exposure on systemic inflammation are independent.

Effect of long-term exposure to fine particulate matter on lung function decline and risk of chronic obstructive pulmonary disease in Taiwan: a longitudinal, cohort study

BACKGROUNDnInformation on the effects of long-term exposure to fine particulate matter with an aerodynamic diameter of 2·5 μm or less (PM2·5) on lung health is scarce. We aimed to investigate the associations between long-term exposure to PM2·5, lung function, and chronic obstructive pulmonary disease (COPD) in a large-scale longitudinal cohort.nnnMETHODSnWe included 285u2008046 participants aged 20 years or older from the Taiwan MJ Health Management Institution cohort, who were recruited between 2001 and 2014 and had spirometric tests during the medical examination visit. We used a satellite-based spatiotemporal model to estimate the 2-year average ground concentration of PM2·5 (for the calendar year of each participants medical examination and for the previous year) at each participants address. We used the generalised linear mixed model to examine the associations between PM2·5 concentrations and lung function and the Cox proportional hazard regression model with time-dependent covariates to investigate the PM2·5 effects on COPD development.nnnFINDINGSnEvery 5 μg/m3 increment in PM2·5 was associated with a decrease of 1·18% for forced vital capacity (FVC), 1·46% for forced expiratory volume in 1 s (FEV1), 1·65% for maximum mid-expiratory flow (MMEF), and 0·21% for FEV1:FVC ratio. The decrease accelerated over time. Additional annual declines were observed for FVC (0·14%), FEV1 (0·24%), MMEF (0·44%), and FEV1:FVC ratio (0·09%). Compared with the participants exposed to the first quartile of PM2·5, participants exposed to the fourth, third, and second quartiles of PM2·5 had a hazard ratio of 1·23 (95% CI 1·09-1·39), 1·30 (1·16-1·46), and 1·39 (1·24-1·56) for COPD development, respectively.nnnINTERPRETATIONnLong-term exposure to ambient PM2·5 is associated with reduced, and faster declines in, lung function. Long-term exposure to ambient PM2·5 is also associated with an increased risk of the incidence of COPD. This study reinforces the urgency of global strategies to mitigate air pollution for improvement of pulmonary health and prevention of COPD.nnnFUNDINGnEnvironmental Health Research Fund of the Chinese University of Hong Kong and PhD Studentship of the Chinese University of Hong Kong.

Exposure to ambient fine particulate matter and semen quality in Taiwan

Objectives Environmental exposure to chemicals has been considered a potential factor contributing to deteriorated semen quality. However, previous literature on exposure to air pollution and semen quality is inconsistent. We therefore investigated the health effects of short-term and long-term exposure to fine particulate matter (PM2.5) on semen quality in Taiwanese men from the general population. Methods A cross-sectional study was conducted among 6475 male participants aged 15–49 years who participated in a standard medical examination programme in Taiwan between 2001 and 2014. Semen quality was assessed according to the WHO 1999 guidelines, including sperm concentration, total motility, progressive motility and morphology. Three-month and 2-year average PM2.5 concentrations were estimated at each participant’s address using a spatiotemporal model based on satellite-derived aerosol optical depth data. Multivariable linear and logistic regressions were used to examine the associations between PM2.5 and semen quality. Results A robust association was observed between exposure to PM2.5 and decreased normal morphology. Every increment of 5u2009µg/m3 in 2-year average PM2.5 was significantly associated with a decrease of 1.29% in sperm normal morphology and a 26% increased risk of having the bottom 10% of sperm normal morphology, after adjusting for a wide range of potential confounders (p<0.001). On the other hand, an increment of 5u2009µg/m3 in 2-year average PM2.5 was associated with an increase of 1.03×106/mL in sperm concentration and a 10% decreased risk of being the bottom 10% of sperm concentration (both p<0.001). Similar results were found for 3-month PM2.5. Conclusions Exposure to ambient PM2.5 air pollution is associated with a lower level of sperm normal morphology and a higher level of sperm concentration.

Long-term exposure to ambient particulate matter (PM2.5) is associated with platelet counts in adults

BACKGROUNDnThe prothrombotic effects of particulate matter (PM) may underlie the association of air pollution with increased risks of cardiovascular disease. This study aimed to investigate the association between long-term exposure to PM with an aerodynamic diameter ≤2.5u202fμm (PM2.5) and platelet counts, a marker of coagulation profiles.nnnMETHODSnThe study participants were from a cohort consisting of 362,396 Taiwanese adults who participated in a standard medical examination program between 2001 and 2014. Platelet counts were measured through Complete Blood Count tests. A satellite-based spatio-temporal model was used to estimate 2-year average ambient PM2.5 concentration at each participants address. Mixed-effects linear regression models were used to investigate the association between PM2.5 exposure and platelet counts.nnnRESULTSnThis analysis included 175,959 men with 396,248 observations and 186,437 women with 397,877 observations. Every 10-μg/m3 increment in the 2-year average PM2.5 was associated with increases of 0.42% (95% CI: 0.38%, 0.47%) and 0.49% (95% CI: 0.44%, 0.54%) in platelet counts in men and women, respectively. A series of sensitivity analyses, including an analysis in participants free of cardiometabolic disorders, confirmed the robustness of the observed associations. Baseline data analyses showed that every 10-μg/m3 increment in PM2.5 was associated with higher risk of 17% and 14% of having elevated platelet counts (≥90th percentile) in men and women, respectively.nnnCONCLUSIONSnLong-term exposure to PM2.5 appears to be associated with increased platelet counts, indicating potential adverse effects on blood coagulability.

Dietary Patterns and the Risk of Rhinitis in Primary School Children: A Prospective Cohort Study

This study was to investigate the association between dietary patterns and rhinitis in primary school children. 1,599 students without rhinitis at baseline survey were selected from a primary school children cohort. Information on food consumption, respiratory symptoms, and confounders was collected using questionnaires. Dietary patterns were defined using principal component analysis. Logistic regression was performed to calculate odds ratio (OR) with 95% confidence intervals (95% CI). The incidence of rhinitis during 12 months follow-up was 21.2%. Three patterns were extracted and labeled as pattern I, II and III. Dietary pattern II which had higher factor loadings of legumes, butter, nuts and potatoes was associated with an increased risk of rhinitis (OR: 1.34, 95% CI: 1.01–1.87) when the highest tertile of pattern score was compared to the lowest tertile, after adjusted for confounders. Besides, every 1-unit increase of score of pattern II was also associated with an increased risk of rhinitis (OR: 1.19, 95% CI: 1.05–1.35). Neither pattern I nor Pattern III was observed to be associated with risk of rhinitis. A diet with higher levels of consumption of legumes, butter, nuts and potatoes may increase the risk of allergic rhinitis in primary school children.

Household cleaning products and the risk of allergic dermatitis: A prospective cohort study with primary-school children

Household cleaning products are widely used by the public, but limited data have been obtained on whether their use induces allergic dermatitis in children.

Increased leisure-time physical activity associated with lower onset of diabetes in 44 828 adults with impaired fasting glucose: a population-based prospective cohort study.

Aims To evaluate the effects of habitual leisure-time physical activity (LTPA) on incident type 2 diabetes in a prospective cohort of Chinese adults with impaired fasting glucose (IFG). Methods 44u2009828 Chinese adults aged 20–80 years with newly detected IFG but free from cardiovascular and cerebrovascular disease were recruited and followed up from 1996 to 2014. Incident type 2 diabetes was identified by fasting plasma glucose ≥7u2009mmol/L. The participants were classified into four categories based on their self-reported weekly LTPA: inactive, low, moderate, or high. Hazard ratios (HRs) and population attributable fractions (PAFs) were estimated with adjustment for established diabetic risk factor. Results After 214u2009148 person-years of follow-up, we observed an inverse dose–response relationship between LTPA and diabetes risk. Compared with inactive participants, diabetes risk in individuals reporting low, moderate and high volume LTPA were reduced by 12% (HR 0.88, 95% CI 0.80 to 0.99; P=0.015), 20% (HR 0.80, 95% CI 0.71 to 0.90; P<0.001), and 25% (HR 0.75, 95% CI 0.67 to 0.83; P<0.001), respectively. At least 19.2% (PAF 19.2%, 95% CI 5.9% to 30.6%) of incident diabetes cases could be avoided if the inactive participants had engaged in WHO recommendation levels of LTPA. This would correspond to a potential reduction of at least 7u2009million diabetic patients in the Greater China area. Conclusions Our results show higher levels of LTPA are associated with a lower risk of diabetes in IFG subjects. These data emphasise the urgent need for promoting physical activity as a preventive strategy against diabetes to offset the impact of population ageing and the growing obesity epidemic.