Fine particulate matter (Particulate matter with diameter ≤ 2.5 μm) is associated with multiple health outcomes, with varying effects across seasons and locations. It remains largely unknown that ...which components of PM2.5 are most harmful to human health.
We systematically searched all the relevent studies published before August 1, 2018, on the associations of fine particulate matter constituents with mortality and morbidity, using Web of Science, MEDLINE, PubMed and EMBASE. Studies were included if they explored the associations between short term or long term exposure of fine particulate matter constituents and natural, cardiovascular or respiratory health endpoints. The criteria for the risk of bias was adapted from OHAT and New Castle Ottawa. We applied a random-effects model to derive the risk estimates for each constituent. We performed main analyses restricted to studies which adjusted the PM2.5 mass in their models.
Significant associations were observed between several PM2.5 constituents and different health endpoints. Among them, black carbon and organic carbon were most robustly and consistently associated with all natural, cardiovascular mortality and morbidity. Other potential toxic constituents including nitrate, sulfate, Zinc, silicon, iron, nickel, vanadium, and potassium were associated with adverse cardiovascular health, while nitrate, sulfate and vanadium were relevant for adverse respiratory health outcomes.
Our analysis suggests that black carbon and organic carbon are important detrimental components of PM2.5, while other constituents are probably hazardous to human health. However, more studies are needed to further confirm our results.
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•The first systematic review of both short term and long term exposure to PM2.5 constituents and related health effects.•Both Mortality and Morbidity have been considered.•BC and OC are constituents that are most likely to cause adverse health effects.
Associations between ambient temperature and cardiovascular morbidity have been well studied worldwide; however, few studies determined the cardiovascular disease burden attributable to temperature. ...We aimed to assess the risk attributed to temperature based on the exposure-lag-response relationship between temperature and circulatory diseases.
We collected daily time series data of emergency hospital admissions, mean temperature, and air pollution concentrations from January 2005 to December 2012 in Hong Kong. The association with temperature was modeled using a distributed lag nonlinear model integrated in quasi-Poisson regression. The cumulated effects of cold/hot temperature were abstracted. Attributable risk measures because of below optimal temperature (OT) were calculated to summarize the disease burden, and further separated into contributions from moderate and extreme cold temperatures. We observed significant nonlinear and delayed cold effect but no apparent hot effect lasting for 3 weeks on emergency circulatory hospitalizations. Compared with the identified OT at 23.0°C, the cumulative relative risk during 0 to 21 lag days was 1.69 (95% confidence interval, 1.56-1.82) for extreme cold (first percentile) and 1.22 (95% confidence interval, 1.15-1.29) for moderate cold temperature (10th percentile). Cold temperatures were responsible for temperature-related circulatory emergency hospitalizations, with attributable fraction of 6.33% for moderate cold and 0.82% for extreme cold while inducing 33 030 and 4257 cases, respectively. Several specific causes of cardiovascular diseases showed higher vulnerability.
Moderate cold weather was responsible for a considerable attributable risk for cardiovascular diseases. The temperature-related hospitalizations risk found in this study may provide evidence for guiding the public health policies and preventions for cardiovascular diseases.
Though rainfall is recognized as one of the main mechanisms to reduce atmospheric particulate pollution, few studies have quantified this effect, particularly the corresponding lag effect and ...threshold. This study aimed to investigate the association between rainfall and air quality using a distributed lag non-linear model. Daily data on ambient PM2.5 and PM2.5–10 (particulate matter with an aerodynamic diameter less than 2.5 μm and from 2.5 to 10 μm) and meteorological factors were collected in Guangzhou and Xi'an from 2013 to 2014. A better washout effect was found for PM2.5–10 than for PM2.5, and the rainfall thresholds for both particle fractions were 7 mm in Guangzhou and 1 mm in Xi'an. The decrease in PM2.5 levels following rain lasted for 3 and 6 days in Guangzhou and Xi'an, respectively. Rainfall had a better washout effect in Xi'an compared with that in Guangzhou. Findings from this study contribute to a better understanding of the washout effects of rainfall on particulate pollution, which may help to understand the category and sustainability of dust-haze and enforce anthropogenic control measures in time.
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•Relative effect is an approach that links washout effect to precipitation amount.•Particle size plays an important role in washout effect of rainfall.•The threshold is helpful in discriminating whether rainfall can improve air quality.•The lag period lengths determine the improvement of air quality following rain.•Restricted by relative effect, the washout effect to particles is limited.
Washout effects and lag effects of rainfall on daily PM2.5 and PM2.5–10 were calculated and air quality improvement were evaluated.
Ambient fine particulate matter pollution (PM2.5) is one leading cause of disease burden, but no study has quantified the association between daily PM2.5 exposure and life expectancy. We aimed to ...assess the potential benefits in life expectancy by attaining the daily PM2.5 standards in 72 cities of China during 2013-2016.
We applied a two-stage approach for the analysis. At the first stage, we used a generalized additive model (GAM) with a Gaussian link to examine the city-specific short-term association between daily PM2.5 and years of life lost (YLL); at the second stage, a random-effects meta-analysis was used to generate the regional and national estimations. We further estimated the potential gains in life expectancy (PGLE) by assuming that ambient PM2.5 has met the Chinese National Ambient Air Quality Standard (NAAQS, 75 μg/m3) or the ambient air quality guideline (AQG) of the World Health Organization (WHO) (25 μg/m3). We also calculated the attributable fraction (AF), which denoted the proportion of YLL attributable to a higher-than-standards daily mean PM2.5 concentration. During the period from January 18, 2013 to December 31, 2016, we recorded 1,226,849 nonaccidental deaths in the study area. We observed significant associations between daily PM2.5 and YLL: each 10 μg/m3 increase in three-day-averaged (lag02) PM2.5 concentrations corresponded to an increment of 0.43 years of life lost (95% CI: 0.29-0.57). We estimated that 168,065.18 (95% CI: 114,144.91-221,985.45) and 68,684.95 (95% CI: 46,648.79-90,721.11) years of life lost can be avoided by achieving WHO's AQG and Chinese NAAQS in the study area, which corresponded to 0.14 (95% CI: 0.09-0.18) and 0.06 (95% CI: 0.04-0.07) years of gain in life expectancy for each death in these cities. We observed differential regional estimates across the 7 regions, with the highest gains in the Northwest region (0.28 years of gain 95% CI: 0.06-0.49) and the lowest in the North region (0.08 95% CI: 0.02-0.15). Furthermore, using WHO's AQG and Chinese NAAQS as the references, we estimated that 1.00% (95% CI: 0.68%-1.32%) and 0.41% (95% CI: 0.28%-0.54%) of YLL could be attributable to the PM2.5 exposure at the national level. Findings from this study were mainly limited by the unavailability of data on individual PM2.5 exposure.
This study indicates that significantly longer life expectancy could be achieved by a reduction in the ambient PM2.5 concentrations. It also highlights the need to formulate a stricter ambient PM2.5 standard at both national and regional levels of China to protect the population's health.
The combined health impact of physical activity (PA) and air pollution on chronic obstructive pulmonary disease (COPD) remains unclear. We investigated the joint effects of habitual PA and long-term ...fine particulate matter (PM
) exposure on COPD incidence in a prospective population-based cohort.
A prospective cohort study was conducted using data from the UK Biobank. Incidence of COPD was ascertained through linkage to the UK National Health Services register. Annual mean PM
concentration was obtained using land use regression model. PA was measured by questionnaire and wrist-worn accelerometer. Cox proportional hazard models were applied to examine the associations between PM
, PA, and COPD. Additive and multiplicative interactions were examined.
A total of 266,280 participants free of COPD at baseline were included in data analysis with an average follow-up of 10.64 years, contributing to around 2.8 million person-years. Compared with participants with low level of PA, those with higher PA levels had lower risks of COPD incidence hazard ratio (HR): 0.769, 95% CI: 0.720, 0.820 for moderate level; HR: 0.726, 95% CI: 0.679, 0.776 for high level. By contrast, PM
was associated with increased risk of COPD (HR per interquartile range increment: 1.065, 95% CI: 1.032, 1.099). Limited evidence of interaction between habitual PA and PM
exposure was found. Similar results were found for accelerometer-measured PA.
Our study suggests that habitual PA could reduce risk of COPD incidence, and such protective effects were not affected by ambient PM
pollution exposure.
Understanding the temporal trend of the disease burden of stroke and its attributable risk factors in China, especially at provincial levels, is important for effective prevention strategies and ...improvement. The aim of this analysis from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) is to investigate the disease burden of stroke and its risk factors at national and provincial levels in China from 1990 to 2019.
Following the methodology in the GBD 2019, the incidence, prevalence, mortality, and disability-adjusted life-years (DALYs) of stroke cases in the Chinese population were estimated by sex, age, year, stroke subtypes (ischaemic stroke, intracerebral haemorrhage, and subarachnoid haemorrhage), and across 33 provincial administrative units in China from 1990 to 2019. Attributable mortality and DALYs of underlying risk factors were calculated by a comparative risk assessment.
In 2019, there were 3·94 million (95% uncertainty interval 3·43–4·58) new stroke cases in China. The incidence rate of stroke increased by 86·0% (73·2–99·0) from 1990, reaching 276·7 (241·3–322·0) per 100 000 population in 2019. The age-standardised incidence rate declined by 9·3% (3·3–15·5) from 1990 to 2019. Among 28·76 million (25·60–32·21) prevalent cases of stroke in 2019, 24·18 million (20·80–27·87) were ischaemic stroke, 4·36 million (3·69–5·05) were intracerebral haemorrhage, and 1·58 million (1·32–1·91) were subarachnoid haemorrhage. The prevalence rate increased by 106·0% (93·7–118·8) and age-standardised prevalence rate increased by 13·2% (7·7–19·1) from 1990 to 2019. In 2019, there were 2·19 million (1·89–2·51) deaths and 45·9 million (39·8–52·3) DALYs due to stroke. The mortality rate increased by 32·3% (8·6–59·0) from 1990 to 2019. Over the same period, the age-standardised mortality rate decreased by 39·8% (28·6–50·7) and the DALY rate decreased by 41·6% (30·7–50·9). High systolic blood pressure, ambient particulate matter pollution exposure, smoking, and diet high in sodium were four major risk factors for stroke burden in 2019. Moreover, we found marked differences of stroke burden and attributable risk factors across provinces in China from 1990 to 2019.
The disease burden of stroke is still severe in China, although the age-standardised incidence and mortality rates have decreased since 1990. The stroke burden in China might be reduced through blood pressure management, lifestyle interventions, and air pollution control. Moreover, because substantial heterogeneity of stroke burden existed in different provinces, improved health care is needed in provinces with heavy stroke burden.
National Key Research and Development Program of China and Taikang Yicai Public Health and Epidemic Control Fund.
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•Few studies have identified susceptible windows for air pollution and gestational diabetes mellitus (GDM) at a weekly level.•Most susceptible exposure window for SO2 is from 4th–10th ...gestational weeks.•The risk of GDM might be greater among women taking folic acid supplements.
Evidence concerning the effect of ambient air pollution exposure on gestational diabetes mellitus (GDM) is limited. No published studies have examined maternal weekly air pollution exposure and GDM, and the possible effect modification by folic acid supplementation has not been assessed.
To evaluate the association between air pollution exposure and GDM at trimester and weekly levels, and to explore the potential effect modification by folic acid supplementation.
A total of 5421 pregnant women were recruited during 2011–2014 in Guangzhou, China. Daily PM2.5, PM10, SO2 and NO2 levels were collected from 10 monitoring stations. Individual's exposure during pregnancy was estimated using inverse-distance weighting approach. Binary logistic regression was used to examine the trimester-specific association between air pollution exposure and GDM. Distributed lag models (DLMs) were applied to estimate maternal weekly air pollution exposure and GDM. Stratified analyses by folic acid supplementation and interaction test were performed.
The GDM incidence was 11.69%. An interquartile range (IQR) increase in first trimester SO2 was associated with increased GDM risk in the single pollutant model, the adjusted odds ratio (aOR) and 95% confidence interval (CI) was 1.22 (1.02–1.47). In DLMs, an IQR increase in SO2 during 4th to 10th gestational weeks was associated with increased GDM risk, with the strongest effect in the 7th gestational week. When stratified by maternal folic acid supplementation, first trimester exposure to SO2 was associated with increased GDM risk among women taking folic acid supplements (aOR = 1.25, 95% CI: 1.03–1.53) and P value for interaction was 0.13. No significant effects were observed for PM2.5, PM10 and NO2.
First trimester exposure to SO2 was associated with increased GDM risk, especially during the 4th to 10th gestational weeks. The effect might be stronger among women taking folic acid supplements.
In the past decade, the most prevalent norovirus genotype causing viral gastroenteritis outbreaks worldwide, including China, has been GII.4. In winter 2014-15, norovirus outbreaks in Guangdong, ...China, increased. Sequence analysis indicated that 82% of the outbreaks were caused by a norovirus GII.17 variant.
Monitoring and predicting dengue incidence facilitates early public health responses to minimize morbidity and mortality. Weather variables are potential predictors of dengue incidence. This study ...explored the impact of weather variability on the transmission of dengue fever in the subtropical city of Guangzhou, China.
Time series Poisson regression analysis was performed using data on monthly weather variables and monthly notified cases of dengue fever in Guangzhou, China for the period of 2001-2006. Estimates of the Poisson model parameters was implemented using the Generalized Estimating Equation (GEE) approach; the quasi-likelihood based information criterion (QICu) was used to select the most parsimonious model.
Two best fitting models, with the smallest QICu values, are selected to characterize the relationship between monthly dengue incidence and weather variables. Minimum temperature and wind velocity are significant predictors of dengue incidence. Further inclusion of minimum humidity in the model provides a better fit.
Minimum temperature and minimum humidity, at a lag of one month, are positively associated with dengue incidence in the subtropical city of Guangzhou, China. Wind velocity is inversely associated with dengue incidence of the same month. These findings should be considered in the prediction of future patterns of dengue transmission.
Previous studies have reported that maternal exposure to particles with aerodynamic diameter <2.5 μm (PM2.5) is associated with birth outcomes. However, a multicity birth cohort study has not been ...conducted in China, and the attributable fraction of adverse birth outcomes due to PM2.5 exposure remains unknown.
We examined associations in a birth cohort of 1,455,026 mother-and-live-birth pairs who were followed up from the first hospital visit for pregnancy until the birth of the baby during 2014–2017 in nine cites of the Pearl River Delta (PRD) region, China. The PM2.5 exposures were estimated based on the air pollution concentrations of the nearby monitors. Cox proportional hazards regressions were employed to examine the associations.
We found 1% (HR = 1.01; 95% CI: 1.00, 1.02), 6% (HR = 1.06; 95% CI: 1.05, 1.07), and 7% (HR = 1.07; 95% CI: 1.06, 1.08) increases in risk of PTB and 20% (HR = 1.20; 95% CI: 1.18, 1.22), 18% (HR = 1.18; 95% CI: 1.15, 1.20), and 20% (HR = 1.20; 95% CI: 1.17, 1.23) increases in risk of LBW, with each 10 μg/m3 increase in PM2.5 from trimester 1 to trimester 3, respectively. For PTB, highest HRs were observed during trimester 3, as for LBW, stronger effect were observed during trimester 1 and trimester 3. We further estimated that 7.84% (95% CI: 6.21%, 9.50%) of PTB and 14.85% (95% CI: 13.00%, 16.61%) of the LBW cases could be attributable to PM2.5 exposure during the third trimester.
The results indicate that maternal PM2.5 exposure is a risk factor for both LBW and PTB, and responsible for considerable burdens of PTB and LBW in the Pearl River Delta region.
•We examined the effects of PM2.5 on preterm birth and low birth weight.•PM2.5 exposure was found to be associated with increased risk of preterm birth.•PM2.5 exposure was observed to be associated with increased risk of low birth weight.•Substantial burden of preterm birth and low birth weight could be attributable to PM2.5 exposure.