ABSTRACT
Greenspace may bring benefits to human health. Evidence on greenness and health has accumulated in western countries, and several reviews have summarized such evidence. Researchers have also conducted some studies on greenspace and human health in Chinese population, but no prior review has pooled or summarized them. To provide more comprehensive evidence on this topic, we searched and summarized studies on greenspace and health that were conducted specifically in Chinese population. We found that a certain number of studies have been conducted in China, and the evidence indicates that greenspace exposure may reduce the odds of cardiovascular diseases, mental health disorders, adverse birth outcomes as well as mortality. However, most of the current reported studies were of cross-sectional design or randomized controlled trails targeting short-term effects, and prospective cohort studies were scarce. Moreover, greenness exposure was mainly assessed using greenness index like normalized difference vegetative index (NDVI), which were static and cannot distinguish construction and species of greenspaces. Future prospective studies with more precise greenness exposure assessment are warranted to evaluate the prior findings.
ABSTRACT
Objective@#To evaluate the association of long-term ambient fine particulate matters (PM2.5) exposure with elevated blood pressure in children.@*Methods@#From April 2012 to June 2013, we used cluster randomized sampling method to investigate 9 354 children aged 5-17 years old from 68 primary and middle schools in the seven Northeastern Cities (Shenyang, Dalian, Fushun, Anshan, Benxi, Liaoyang and Dandong) in Liaoning Province, and measured their blood pressure (BP). A spatial statistical model nested by aerosol optical depth (AOD) was used to inverse PM2.5 concentrations. Generalized additive model was used to quantify the association between PM2.5 exposure and blood pressure in children. To examine the associations, two-level regression model was used to evaluate individual characteristics′ modifying effect on the health influence of PM2.5.@*Results@#The prevalence of hypertension in children was 13.78% (1 289/9 354). The results showed that there was an associations between hypertension and pollutants, and the multivariable regression analysis indicated that the increase in mean systolic blood pressure (SBP), diastolic blood pressure (DBP), and the OR of hypertension associated with a 10 μg/m3 increase for PM2.5 were 3.12 (95%CI: 2.71-3.54) mmHg (1 mmHg=0.133 kPa), 1.45 (95%CI:1.12-1.78) mmHg, and 1.55 (95%CI: 1.10-2.19), respectively. Compared with non-breastfeeding children (OR=2.10, 95%CI: 1.39-3.17), children who were breastfeeding (OR=1.49, 95%CI: 1.00-2.20) exhibited consistently weaker effects, and the interaction effect of P value was 0.002.@*Conclusion@#Study findings indicate that long-term exposure to PM2.5 is associated with increased arterial BP and hypertension among the children. Breastfeeding may reduce this association.