Acute effects of air pollutants on adverse birth outcomes in Changsha, China: A population data with time-series analysis from 2015 to 2017

How climate change degrades child health: A systematic review and meta-analysis

BACKGROUND

Children are more vulnerable than adults to climate-related health threats, but reviews examining how climate change affects human health have been mainly descriptive and lack an assessment of the magnitude of health effects children face. This is the first systematic review and meta-analysis that identifies which climate-health relationships pose the greatest threats to children.

OBJECTIVES

We reviewed epidemiologic studies to analyse various child health outcomes due to climate change and identify the relationships with the largest effect size. We identify population-specific risks and provide recommendations for future research.

METHODS

We searched four large online databases for observational studies published up to 5 January 2023 following PRISMA (systematic review) guidelines. We evaluated each included study individually and aggregated relevant quantitative data. We used quantitative data in our meta-analysis, where we standardised effect sizes and compared them among different groupings of climate variables and health outcomes.

RESULTS

Of 1301 articles we identified, 163 studies were eligible for analysis. We identified many relationships between climate change and child health, the strongest of which was increasing risk (60 % on average) of preterm birth from exposure to temperature extremes. Respiratory disease, mortality, and morbidity, among others, were also influenced by climate changes. The effects of different air pollutants on health outcomes were considerably smaller compared to temperature effects, but with most (16/20 = 80 %) pollutant studies indicating at least a weak effect. Most studies occurred in high-income regions, but we found no geographical clustering according to health outcome, climate variable, or magnitude of risk. The following factors were protective of climate-related child-health threats: (i) economic stability and strength, (ii) access to quality healthcare, (iii) adequate infrastructure, and (iv) food security. Threats to these services vary by local geographical, climate, and socio-economic conditions. Children will have increased prevalence of disease due to anthropogenic climate change, and our quantification of the impact of various aspects of climate change on child health can contribute to the planning of mitigation that will improve the health of current and future generations.

Association of Fine Particulate Matter and Its Components with Macrosomia: A Nationwide Birth Cohort Study of 336 Chinese Cities

To examine the associations between macrosomia risk and exposure to fine particulate matter (PM2.5) and its chemical components during pregnancy, we collected birth records between 2010 and 2015 in mainland China from the National Free Preconception Health Examination Project and used satellite-based models to estimate concentrations of PM2.5 mass and five main components, namely, black carbon (BC), organic carbon (OC), nitrate (NO3-), sulfate (SO42-), and ammonium (NH4+). Associations between macrosomia risk and prenatal exposure to PM2.5 were examined by logistic regression analysis, and the sensitive subgroups were explored by stratified analyses. Of the 3,248,263 singleton newborns from 336 cities, 165,119 (5.1%) had macrosomia. Each interquartile range increase in concentration of PM2.5 during the entire pregnancy was associated with increased risk of macrosomia (odds ratio (OR) = 1.18; 95% confidence interval (CI), 1.17-1.20). Among specific components, the largest effect estimates were found on NO3- (OR = 1.36; 95% CI, 1.35-1.38) followed by OC (OR = 1.23; 95% CI, 1.22-1.24), NH4+ (OR = 1.22; 95% CI, 1.21-1.23), and BC (OR = 1.21; 95% CI, 1.20-1.22). We also that found boys, women with a normal or lower prepregnancy body mass index, and women with irregular or no folic acid supplementation experienced higher risk of macrosomia associated with PM2.5 exposure.

The short-term effects of air pollution exposure on preterm births in Chongqing, China: 2015-2020

Accumulating evidence suggested that the risk of preterm births (PTBs) following prenatal exposure to air pollution was inconclusive. The aim of this study is to investigate the relationship between air pollution exposure in the days before delivery and PTB and assess the threshold effect of short-term prenatal exposure to air pollution on PTB. This study collected data including meteorological factors, air pollutants, and information in Birth Certificate System from 9 districts during 2015-2020 in Chongqing, China. Generalized additive models (GAMs) with the distributed lag non-linear models were conducted to assess the acute impact of air pollutants on the daily counts of PTB, after controlling for potential confounding factors. We observed that PM2.5 was related to increased occurrence of PTB on lag 0-3 and lag 10-21 days, with the strongest on the first day (RR = 1.017, 95%CI: 1.000-1.034) and then decreasing. The thresholds of PM2.5 for lag 1-7 and 1-30 days were 100 μg/m3 and 50 μg/m3, respectively. The lag effect of PM10 on PTB was very similar to that of PM2.5. In addition, the lagged and cumulative exposure of SO2 and NO2 was also associated with the increased risk of PTB. The lag relative risk and cumulative relative risk of CO exposure were the strongest, with a maximum RR at lag 0 (RR = 1.044, 95%CI: 1.018, 1.069). Importantly, the exposure-response curve of CO showed that RR increased rapidly when the concentration exceeded 1000 μg/m3. This study indicated significant associations between air pollution and PTB. The relative risk decreases with day lag, while the cumulative effect increases. Thus, pregnant women should understand the risk of air pollution and try to avoid high concentration exposure.

Acute and chronic maternal exposure to fine particulate matter and prelabor rupture of the fetal membranes: A nation-wide survey in China

BACKGROUND

Prelabor rupture of the fetal membranes (PROM) is a major contributor to adverse perinatal outcomes. Some epidemiologic studies explored the association between maternal PM_2.5 exposure and PROM but failed to treat the labor induction and prelabor cesarean section as censored observations.

OBJECTIVE

We aimed to evaluated whether acute and chronic maternal ambient PM_2.5 exposure may increase the risk of PROM in China.

METHODS

This study was based on the China Labor and Delivery Survey, a nationwide multicenter investigation. Included in the current analysis were 45,879 singleton spontaneous births in 96 hospitals in mainland China from 2015 to 2017. Outcomes were PROM, preterm PROM (<37 weeks' gestation) and term PROM (≥37 weeks' gestation). Daily concentration of PM_2.5 at 1 km spatial resolution was estimated by gap-filling model. Generalized linear mixed model and mixed effects Cox model were applied to assess the associations of acute (from 0 to 4 days before delivery) and chronic (average gestational and trimester-specific) ambient PM_2.5 exposure with outcomes, respectively.

RESULTS

Significant associations were found between acute PM_2.5 exposures (per interquartile range increase) and the risk of preterm PROM (OR = 1.11; 95 % CI: 1.03, 1.19 for PM_2.5 on delivery day; OR = 1.10; 95 % CI: 1.02, 1.18 for PM_2.5 1 day before delivery) but not for term PROM. An interquartile range increase in PM_2.5 during the second trimester was associated with elevated risks of PROM (HR = 1.14; 95 % CI: 1.07, 1.22), preterm PROM (HR = 1.22; 95 % CI: 1.02, 1.45) and term PROM (HR = 1.13; 95 % CI: 1.06, 1.22), respectively. Women who were less educated, obese, or gave birth in a cold season appeared to be more sensitive to ambient PM_2.5 exposure.

CONCLUSION

Our findings suggest that both acute and chronic maternal exposures to ambient PM_2.5 during pregnancy are risk factors for PROM.

Prenatal exposure to air pollution and the risk of macrosomia: Identifying windows of susceptibility

This study explores the effects of prenatal exposure to air pollution on the risk of macrosomia and its window of susceptibility. We conducted a retrospective cohort study utilizing records of birth certificates for all full-term live newborns born in Xi'an city, China from January 1, 2015, to December 31, 2018.Weekly- and trimester-specific exposures of PM_2.5, PM₁₀, NO₂, and O₃ during pregnancy were calculated by inverse distance weighting (IDW) based on their residences. Cox proportional hazard model and distributed lag models (DLMs) were performed to estimate the effects of air pollution exposure during pregnancy on macrosomia risk and its window of susceptibility. In total, 318,323 full-term newborns were identified, including 24,996 (7.8%) cases of macrosomia. An IQR increase in PM_2.5 exposure (45.46 μg/m³) from the 33rd until the 37th weeks of gestation was positively associated with an elevated risk of macrosomia, with the strongest effect in the 37th weeks (HR = 1.007, 95%CI: 1.002-1.013). The window of susceptibility for NO₂ exposure on macrosomia risk was in the 29th-35th gestational weeks, with the strongest effect in the 34th weeks (IQR = 21.96 μg/m³, HR = 1.006, 95%CI:1.000-1.013). For prenatal exposure to O₃, 5th-24th weeks of gestation was identified as susceptible windows for elevated risk of macrosomia, with the strongest associations observed in the 15th weeks (IQR = 80.53 μg/m³, HR = 1.022, 95%CI: 1.011-1.033). However, we did not observe any associations between weekly exposure of PM₁₀ and macrosomia. Our findings imply that the windows of susceptibility to PM_2.5 and NO₂ exposure on macrosomia are mainly in late pregnancy, whereas the windows of susceptibility to O₃ exposure are in early and middle pregnancy.

Time series analysis of short-term effects of particulate matter pollution on the circulatory system disease mortality risk in Lishui District, China

Epidemiological evidence has shown a significant association between short-term exposure to air pollution and mortality risk for circulatory system diseases (CSD). However, informative insights on the significance and magnitude of its relationship in the process of government interventions on abating air pollution are still lacking, particularly in a burgeoning Chinese city. In this study, we conducted a time series study in Lishui District, Nanjing, to examine the effect of ambient particulate matter (PM), e.g., PM_2.5 and PM₁₀, on daily death counts of CSD which included cardiovascular disease (CVD), cerebrovascular disease (CEVD), and arteriosclerotic heart disease (ASHD) mortality from January 1, 2015, to December 31, 2019. The results revealed that each 10 μg/m³ increase in PM_2.5 and PM₁₀ concentration at lag0 day was associated with an increase of 1.33% (95% confidence interval, 0.08%, 2.60%) and 1.12% (0.43%, 1.82%) in CSD mortality; 2.42% (0.44%, 4.43%) and 1.43% (0.32%, 2.55%) in CVD mortality; 1.20% (- 0.31%, 2.73%) and 1.21% (0.38%, 2.05%) in CEVD mortality; and 2.78% (0.00%, 5.62%) and 1.66% (0.14%, 3.21%) in ASHD mortality, respectively. For cumulative risk, the corresponding increase in daily mortality for the same change in PM_2.5 concentration at lag03 day was significantly associated with 1.94% (0.23%, 3.68%), 3.17% (0.58%, 5.84%), 2.38% (0.17%, 4.63%), and 4.92% (1.18%, 8.81%) for CSD, CVD, CEVD, and ASHD, respectively. The exposure-response curves were approximately nonlinear over the entire exposure range of the PM concentrations. We also analyzed the effect modifications by season (warm or cold), age group (0-64 years, 65-74 years, or ≥ 75 years), and sex (male or female). Although not statistically significant, stratified analysis showed greater vulnerability to PM exposure for cold season, population over 65 years of age, and female group.

Association between Maternal Exposure to Ambient Air Pollution and the Risk of Preterm Birth: A Birth Cohort Study in Chongqing, China, 2015-2020

Recent study results on the association between maternal exposure to ambient air pollution with preterm birth have been inconsistent. The sensitive window of exposure and influence level of air pollutants varied greatly. We aimed to explore the association between maternal exposure to ambient air pollutants and the risk of preterm birth, and to estimate the sensitive exposure time window. A total of 572,116 mother–newborn pairs, daily concentrations of air pollutants from nearest monitoring stations were used to estimate exposures for each participant during 2015–2020 in Chongqing, China. We applied a generalized additive model and estimated RRs and 95% CIs for preterm birth in each trimester and the entire pregnancy period. In the single-pollutant model, we observed that each 10 μg/m³ increase in PM_2.5 had a statistically significant effect on the third trimester and entire pregnancy, with RR = 1.036 (95% CI: 1.021, 1.051) and RR = 1.101 (95% CI: 1.075, 1.128), respectively. Similarly, for each 10 μg/m³ increase in PM₁₀, there were 2.7% (RR = 1.027, 95% CI: 1.016, 1.038) increase for PTB on the third trimester, and 3.8% (RR = 1.038, 95% CI: 1.020, 1.057) increase during the whole pregnancy. We found that for each 10 mg/m³ CO increases, the relative risk of PTB increased on the first trimester (RR = 1.081, 95% CI: 1.007, 1.162), second trimester (RR = 1.116, 95% CI: 1.035, 1.204), third trimester (RR = 1.167, 95% CI: 1.090, 1.250) and whole pregnancy (RR = 1.098, 95% CI: 1.011, 1.192). No statistically significant RR was found for SO₂ and NO₂ on each trimester of pregnancy. Our study indicates that maternal exposure to high levels of PM_2.5 and PM₁₀ during pregnancy may increase the risk for preterm birth, especially for women at the late stage of pregnancy. Statistically increased risks of preterm birth were associated with CO exposure during each trimester and entire pregnancy. Reducing exposure to ambient air pollutants for pregnant women is clearly necessary to improve the health of infants.

Prenatal air pollution exposure increases the risk of macrosomia: evidence from a prospective cohort study in the coastal area of China

Effects of prenatal ambient air pollution exposure could increase the risk of adverse pregnancy outcomes, which have been well documented by various studies. However, only very few studies investigated the effects on macrosomia. This study investigated the effects of prenatal air pollution exposure on the risk of macrosomia in a coastal city of China. Data of birth outcomes and air pollution in a coastal city in China between November 1, 2013, and December 31, 2017, were collected. Finally, 58,713 eligible births, including 8159 (13.9%) macrosomia and 50554 (86.1%) normal birth weight (NBW) infants, were included in the analysis. Logistic regression analyses were used to evaluate the effects of prenatal air pollution exposure on macrosomia. In the single-pollutant models, each 10 μg/m³ increase of PM_2.5, PM₁₀, and SO₂ exposures, during the entire pregnancy or three trimesters, were related to elevated risk of macrosomia (adjusted RR, 95% CI) ranging from 1.018 (1.001, 1.035) to 1.314 (1.188, 1.454). In addition, O₃ exposure in the first trimester (adjusted RR =1.034, 95% CI 1.009, 1.059) also increased the macrosomia risk. Prenatal PM_2.5, PM₁₀, and SO₂ exposure could significantly increase the risk of macrosomia. These findings need to be further verified in more studies with multiple coastal cities included.

Long-term impact of ambient air pollution on preterm birth in Xuzhou, China: a time series study

Accumulating evidence witnesses the negative influence of air pollution on human health, but the relationship between air pollution and premature babies has been inconsistent. In this study, the association between weekly average concentration of air pollutants and preterm birth (PTB) was conducted in Xuzhou, a heavy industry city, in China. We constructed a distributed lag non-linear model (DLNM), an ecological study, to access the associations between ambient air pollutants and PTB in this study. Totally, 5408 premature babies were included, and the weekly average levels of PM_2.5, PM₁₀, SO₂, NO₂, O₃, and CO were 61.24, 110.21, 22.55, 40.55, 104.45, and 1.04 mg/m³, respectively. We found that PM_2.5, PM₁₀, SO₂, and NO₂ significantly increased the risk of PTB, and the susceptibility windows of these contaminants were the second trimester and third trimester (from 12 to 29 weeks). Every 10 μg/m³ increase of PM_2.5, PM₁₀, SO₂, and NO₂, the greatest relative risk (RR) values and 95% confidence interval (CI) on PTB were 1.0075 [95% CI, 1.0019-1.0131], 1.0053 [95% CI, 1.0014-1.0092], 1.0203 [95% CI, 1.0030-1.0379], and 1.0170 [95% CI, 1.0052-1.0289] in lag 16th, 18th, 19th, and 20th gestational weeks, respectively. No significant influence of O₃ and CO were found on preterm birth. Subgroup analysis showed that the risk of premature delivery was higher for younger pregnant women and in warm season. This finding shows that prenatal exposure to ambient air pollutants is associated with preterm birth, and there existed an exposure window period.

Association between short-term exposure to sulfur dioxide and carbon monoxide and ischemic heart disease and non-accidental death in Changsha city, China

Background

To investigate the effects of short-term exposure to sulfur dioxide (SO₂) and carbon monoxide (CO) in the central and southern China areas on ischemic heart disease (IHD) and non-accidental deaths.

Method

We investigated the associations between short-term exposure to SO₂ and CO in a city in south-central China and IHD and non-accidental death using a time-series design and generalized additive models with up to a 5-day lag adjusting for day of the week, temperature, air pressure, wind speed, and relative humidity. The relative risks of IHD and non-accidental death per 10-unit increase in SO₂ and CO were derived from zero to five days in single-pollutant models.

Results

Between 2016 and 2018, a total of 10,507 IHD and 44,070 non-accidental deaths were identified. The largest significant relative risk for IHD death was lag 02 for both SO₂ (1.080; 95% confidence interval: 1.075–1.084) and CO (5.297; 95% confidence interval: 5.177–5.418) in single-pollutants models. A significant association was shown at all lag multiple-day moving averages. Two-pollutant models identified an association between SO₂ and mortality when adjusting for CO. In stratified analyses, SO₂ exhibited a stronger association with death during the cold season, while CO exhibited a stronger association with mortality from IHD during the warm season. The risk of death was more robust in the elderly for both pollutants, but was greater in men for CO and in women for SO₂.

Conclusions

Overall, we found an association between short-term exposure to low-level SO₂ and CO and the risk of IHD and non-accidental death.

Prenatal exposure to ambient air pollution and adverse pregnancy outcomes in Ahvaz, Iran: a generalized additive model

OBJECTIVE

There is some evidence about the short-term effects of air pollutants on adverse pregnancy outcomes. The aim of this study was to determine the association between air pollutants and spontaneous abortion, stillbirth, gestational hypertension, preeclampsia, gestational diabetes and macrosomia in Ahvaz, which is one of the most polluted cities in the Middle East.

METHODS

Data on adverse pregnancy outcomes and air pollutants including ozone (O₃), nitric oxide (NO), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), carbon monoxide (CO), particles with a diameter of less than 10 µm (PM₁₀) and particles with a diameter less than 2.5 µm (PM_2.5) were inquired from the Health Department of Ahvaz Jundishapur University of Medical Sciences and the Environmental Protection Agency of Khuzestan Province for the years 2008-2018. A time series analysis using the generalized additive model (GAM) with up to 6-day lags was used.

RESULTS

The results showed that the SO₂ pollutant on 0, 1, 3, 4, and 6-day lags and PM₁₀ on lag 0 had direct and significant associations with spontaneous abortion. NO, NO₂ and CO on 0-6-day lags, and O₃ on 6-day lags showed direct and significant associations with preeclampsia. NO and NO₂ pollutants showed significant and direct associations with gestational diabetes, during 0- and 6-day lags. NO on 0-, 3- and 4-day lags, CO in all 0-6-day lags and PM_2.5 on 1-, 3-, 5-, and 6-day lags showed direct and significant associations with macrosomia. None of the pollutants showed significant associations with stillbirth or gestational hypertension.

CONCLUSIONS

The results of this study suggest that some air pollutants are associated with spontaneous abortion, preeclampsia, gestational diabetes and macrosomia. This study further emphasizes the need to control ambient air pollution.

Particulate matter pollution and hospital outpatient visits for endocrine, digestive, urological, and dermatological diseases in Nanjing, China

Clinical or pathological evidence demonstrated that air pollution could undermine other organ systems of human body besides respiratory and circulation systems. Investigations that directly relate hospital outpatient visits for endocrine (ENDO), digestive (DIGE), urological (UROL), and dermatological (DERM) diseases categories with ambient particulate matter (PM) are still lacking, particularly in heavily polluted cities. Here, we conducted a time-series analysis using 812,624, 1,111,342, 539,803, and 741,662 hospital visits for ENDO, DIGE, UROL, and DERM, respectively, in Nanjing, China from 2013 to 2019. A generalized additive model was applied to estimate the exposure-response associations. Results showed that a 10 μg/m³ increase in PM_2.5 concentration on lag 0 day was significantly associated with 0.59% (95% CI: 0.30%, 0.88%), 0.43% (0.15%, 0.70%), 0.36% (0.06%, 0.66%), and 0.65% (0.42%, 0.87%) increase for ENDO, DIGE, UROL, and DERM hospital visits, respectively. The estimated effects of PM₁₀ were slightly smaller but still statistically significant. The magnitude and significance of the associations between PM and four health outcomes were sensitive to additional adjustment for co-pollutants. Exposure-response relationships were linear for PM concentrations lower than 100 μg/m³ but the curves became nonlinear across the full range of exposures due to a flatten slope at higher concentrations. We also explored the effect modifications by season (cold or warm), age (5-18, 18-64, 65-74, or 75+ years), and sex (male or female). Results showed that the DERM-related population aged 65 years or older was more vulnerable to PM exposure, compared with the 5 to 17-year age group; the DERM-related population aged 75 years or older and 65 years or older was more vulnerable to PM_2.5 and PM₁₀ exposure, respectively, compared with the 18 to 64-year age group. Our study provided suggestive evidence that ambient PM pollution was associated with ENDO, DIGE, UROL, and DERM outpatient hospital visits in Nanjing, China.

The Association Between Air Pollution and Low Birth Weight and Preterm Labor in Ahvaz, Iran

PURPOSE

Pregnant women and fetuses are sensitive to air pollution due to physiological changes in pregnancy. The aim of this study was to determine the relationship between exposure to air pollution, low birth weight and preterm labor in Ahvaz.

METHODS

This research was a time-series study. The research sample consisted of all data about low birth weight and preterm labor pregnant women from Imam Khomeini Hospital and Razi Hospital in Ahvaz city. Air pollutant data including O3, NO, NO2, SO2, CO, PM10 and PM2.5 and climate data were collected from the Environmental Protection Agency and the Khuzestan Province during a 10-year period from 2008 to 2018. The generalized additive models (GAMs) with different air pollutant lags up to 6 days were used.

RESULTS

The results of multiple GAM model have shown that there is a direct and significant relationship between exposure to PM10 at 0-6-day lag, SO2 at 2- and 3-day lag and low birth weight. In addition, there was a direct and significant correlation between exposure to NO2, NO, CO and PM2.5 at 0-6-day lag and preterm labor.

CONCLUSION

The results indicate the effect of air pollutants on low birth weight and preterm labor. Therefore, pregnant women should be informed about the negative consequences of air pollution and avoid exposure to polluted air during pregnancy.