[Impact of atmospheric particulate matter at different period of gestation on low birth weight: a meta-analysis].

Objective: To analyze the influence of atmospheric particulate matters (PM(2.5) and PM(10)) on low-birth-weight (LBW) infants at different periods of gestation. Methods: We conducted a systematic literature search for 2 471 articles related to particulate matter and LBW published from January 1st 2000 to January 1st 2016 using the PubMed, Cochrane Library, Web of Science, Science Direct, Chinese Web of Knowledge, Wanfang and Weipu, and the keywords were" air pollution" , "adverse birth outcomes" , "adverse pregnancy outcomes" , "low birth weight/LBW" . According to criteria, 27 literatures were selected and included. Metafor package of the R 3.1.1 Software was used to check the heterogeneity and merge the effect value of the selected literatures, and sensitivity analysis and publication bias were detected and adjusted. Results: A total of 2 471 studies selected form the databases, 27 enrolled in this analysis according to the inclusion and exclusion criteria. Each 10 µg/m(3) increase in PM(2.5) was associated with combined OR values of 1st trimester, 2nd trimester, 3rd trimester and entire gestation at 1.02(95% CI: 0.87-1.19), 1.03 (95% CI: 0.91-1.16) , 1.07 (95%CI: 1.04-1.11) and 1.09 (95%CI: 1.04-1.15), respectively. And 10 µg/m(3) increase in PM(10) was associated with combined OR values of 1st trimester, 2nd trimester, 3rd trimester and entire gestation at 1.66 (95%CI: 1.06-2.61), 1.58 (95%CI:1.28-1.95) , 1.38 (95%CI: 1.23-1.56) and 1.04 (95%CI: 0.99-1.09), respectively. After adjusting the bias of publication, each 10 µg/m(3) increase in PM(2.5) was associated with the risk of low birth weight at 1.11 (95%CI: 1.02-1.21). Conclusion: This meta analysis supports an adverse impact of maternal exposure to particulate air pollution on low birth weight, varying in effects by exposure period.

[Temperature modifies the acute effect of particulate air pollution on mortality in Jiang'an district of Wuhan].

OBJECTIVE: To analyze the temperature modification effect on acute mortality due to particulate air pollution. METHODS: Daily non-accidental mortality, cardiovascular mortality, and respiratory mortality data were obtained from Jiang'an District Center for Disease Control and Prevention. Daily meteorological data on mean temperature and relative humidity were collected from China Meteorological Data Sharing Service System. The daily concentration of particulate matter was collected from Wuhan Environmental Monitoring center. By using the stratified time-series models, we analyzed effects of particulate air pollution on mortality under different temperature zone from 2002 to 2010, meanwhile comparing the difference of age, gender and educational level, in Wuhan city of China. RESULTS: High temperature (daily average temperature > 33.4 ℃) obviously enhanced the effect of PM10 on mortality. With 10 µg/m(3) increase in PM10 concentrations, non-accidental, cardiovascular, and respiratory mortality increased 2.95% (95%CI: 1.68%-4.24%), 3.58% (95%CI: 1.72%-5.49%), and 5.07% (95%CI: 2.03%-9.51%) respectively. However, low temperature (daily average temperature <-0.21 ℃) enhanced PM10 effect on respiratory mortality with 3.31% (95% CI: 0.07%-6.64%) increase. At high temperature, PM10 had significantly stronger effect on non-accidental mortality of female aged over 65 and people with high educational level groups. With an increase of 10 µg/m(3), daily non-accidental mortality increased 4.27% (95% CI:2.45%-6.12%), 3.38% (95% CI:1.93%-4.86%) and 3.47% (95% CI:1.79%-5.18%), respectively. Whereas people with low educational level were more susceptible to low temperature. A 10 µg/m(3) increase in PM10 was associated with 2.11% (95% CI: 0.20%-4.04%) for non-accidental mortality. CONCLUSIONS: Temperature factor can modify the association between the PM10 level and cause-specific mortality. Moreover, the differences were apparent after considering the age, gender and education groups.

[Acute impact of cold spells on mortality during 2001-2011 in Jiang'an district of Wuhan, China].

OBJECTIVE: To evaluate the association between cold spells and nonaccidental mortality from 2001 to 2011 in the Jiang'an District of Wuhan, China. METHODS: We collected mortality data for December 2001 to 2010 and January to March 2002 to 2011 in the study area. According to the International Classification of Diseases, we stratified the mortality data into three cause-specific categories: nonaccidental mortality, cardiovascular mortality, and respiratory mortality. We also obtained meteorological data (from the China Meteorological Administration) and ambient pollution data (from the Wuhan Environmental Monitoring Center) during the same periods. In the present study, a cold spell was defined as 5 or more consecutive days with daily average temperatures below the 5th percentile of daily mean temperatures (2.58 ℃) from January to December in 2001-2011. A distributed lag nonlinear model (DLNM) was applied to assess the acute effect of cold spells on daily nonaccidental mortality. RESULTS: During the study period, the total number of nonaccidental deaths was 17 119, including 9 403 (75.5%) among individuals aged over 65 years; 7 968 (46.5%) people died of cardiovascular disease. According to this definition, there were a total of 13 cold spell events and 111 days of duration in Wuhan during the study period. Study days were divided into three periods: non-cold spell days, 2008 cold spell days, and cold spell days in other years. Average daily mean temperatures of the above three periods were (8.2±4.5), (-0.7±1.4), and (0.8±1.2) ℃, respectively, corresponding to average daily deaths of 14.0±4.2, 18.2±4.5, and 14.9±4.9 for nonaccidental mortality. After adjusting for long-term trends, seasonal trends, weekdays, holidays, and relative humidity, analysis by the DLNM revealed that cold spells were associated with increased mortality risk, with a cumulative relative risk (RR) of 1.56 (95% CI: 1.36-1.79) at lag 0-27 days in 2008, higher than that in other years with 1.23 (95%CI: 1.08-1.41). Cold spells were not significantly associated with respiratory mortality and people under 65 years of age; however, during the 2008 cold spell RR increased to 1.96 (95% CI: 1.62-2.37) and 1.67 (95% CI: 1.43-1.95) for cardiovascular mortality and older adults (≥65 years old), respectively; both males and females had high mortality risk, with RRs of 1.60 (95%CI:1.33-1.92) and 1.50 (95% CI: 1.23-1.84), respectively. The association between cold spells and mortality remained nearly unchanged with and without adjustment for ambient pollutants (PM10, SO2, and NO2) in the DLNMs. CONCLUSION: In Wuhan, both the 2008 cold spell and cold spells in other years were significantly associated with increased nonaccidental mortality. People with cardiovascular disease and elderly adults may be more susceptible to the impact of cold spells on mortality.