Association between long-term exposure to outdoor air pollution and mortality in China: a cohort study

Temperature modification of air pollutants and their synergistic effects on respiratory diseases in a semi-arid city in Northwest China

Air pollutants and temperature are significant threats to public health, and the complex linkages between the environmental factors and their interactions harm respiratory diseases. This study is aimed to analyze the impact of air pollutants and meteorological factors on respiratory diseases and their synergistic effects in Dingxi, a city in northwestern China, from 2018 to 2020 using a generalized additive model (GAM). Relative risk (RR) was employed to quantitatively evaluate the temperature modification on the short-term effects of PM2.5 and O3 and the synergistic effects of air pollutants (PM2.5 and O3) and meteorological elements (temperature and relative humidity) on respiratory diseases. The results indicated that the RRs per inter-quatile range (IQR) rise in PM2.5 and O3 concentrations were (1.066, 95% CI: 1.009-1.127, lag2) and (1.037, 95% CI: 0.975-1.102, lag4) for respiratory diseases, respectively. Temperature stratification suggests that the influence of PM2.5 on respiratory diseases was significantly enhanced at low and moderate temperatures, and the risk of respiratory diseases caused by O3 was significantly increased at high temperatures. The synergy analysis demonstrated significant a synergistic effect of PM2.5 with low temperature and high relative humidity and an antagonistic effect of high relative humidity and O3 on respiratory diseases. The findings would provide a scientific basis for the impact of pollutants on respiratory diseases in Northwest China.

Long-term exposure to air pollution on cardio-respiratory, and lung cancer mortality: a systematic review and meta-analysis

Air pollution is a major cause of specific deaths worldwide. This review article aimed to investigate the results of cohort studies for air pollution connected with the all-cause, cardio-respiratory, and lung cancer mortality risk by performing a meta-analysis. Relevant cohort studies were searched in electronic databases (PubMed/Medline, Web of Science, and Scopus). We used a random effect model to estimate the pooled relative risks (RRs) and their 95% CIs (confidence intervals) of mortality. The risk of bias for each included study was also assessed by Office of Health Assessment and Translation (OHAT) checklists. We applied statistical tests for heterogeneity and sensitivity analyses. The registration code of this study in PROSPERO was CRD42023422945. A total of 88 cohort studies were eligible and included in the final analysis. The pooled relative risk (RR) per 10 μg/m3 increase of fine particulate matter (PM2.5) was 1.080 (95% CI 1.068-1.092) for all-cause mortality, 1.058 (95% CI 1.055-1.062) for cardiovascular mortality, 1.066 (95%CI 1.034-1.097) for respiratory mortality and 1.118 (95% CI 1.076-1.159) for lung cancer mortality. We observed positive increased associations between exposure to PM2.5, PM10, black carbon (BC), and nitrogen dioxide (NO2) with all-cause, cardiovascular and respiratory diseases, and lung cancer mortality, but the associations were not significant for nitrogen oxides (NOx), sulfur dioxide (SO2) and ozone (O3). The risk of mortality for males and the elderly was higher compared to females and younger age. The pooled effect estimates derived from cohort studies provide substantial evidence of adverse air pollution associations with all-cause, cardiovascular, respiratory, and lung cancer mortality.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40201-024-00900-6.

Human health risk assessment model associated with PM2.5 bound metals in paradip port township, India

This study aimed to assess the environmental risk and human health risks associated with PM2.5-bound metals in Paradip city between January 2019 and December 2021. The seasonal average concentrations of PM2.5 were measured 91.43 ± 70.18 μg m-3, 103.40 ± 60.80 μg m-3, 124.74 ± 62.37 μg m-3, and 159.37 ± 77.88 μg m-3 in pre-monsoon, monsoon, post-monsoon, and winter season respectively. The highest and lowest concentrations are estimated in the winter and pre-monsoon season. Paradip city experienced tropical weather conditions with a hot and humid climate. The wind pattern shows that the predominant wind direction was observed from the south-south-west (SSW) direction. The metals in PM2.5 were analysed using an atomic absorption spectrophotometer (AAS) by air-acetylene flame using a hollow cathode lamp. The average metal concentration decreased in the order of Fe > Al > Zn > Pb > Cr > Mn > Ni > Cu > Co > Cd > As. The value of the geo-accumulation index (Igeo) was evaluated >1 for Cd, Fe, and Zn elements. The health risk assessment (HRA) results showed that non-carcinogenic risk (NCR) was higher through the inhalation route followed by ingestion and dermal contact. The cumulative NCR, which is expressed in terms of the hazard index (HI), is greater than 1 for infant (2.78E+00), child (2.53E+00), and adult (1.04E+00) via inhalation pathway. The total carcinogenic risk (TCR) for infants, children, and adults was estimated at 1.45E-04, 7.24E-05 and 1.25E-05, respectively, which exceeded the acceptable limit of 1.00E-06. Our comprehensive research plays an important role in both policymakers and relevant stakeholders for the preparation of city action plans concerning ambient air pollution, which can improve the air quality in and around Paradip city, India.

Potential causal links of long-term air pollution with lung cancer incidence: From the perspectives of mortality and hospital admission in a large cohort study in southern China

Evidence on the potential causal links of long-term air pollution exposure with lung cancer incidence (reflected by mortality and hospital admission) was limited, especially based on large cohorts. We examined the relationship between lung cancer and long-term exposure to particulate matter (PM, including PM2.5 , PM10 and PM10-2.5 ) and nitrogen dioxide (NO2 ) among a large cohort of general Chinese adults using causal inference approaches. The study included 575 592 participants who were followed up for an average of 8.2 years. The yearly exposure of PM and NO2 was estimated through satellite-based random forest approaches and the ordinary kriging method, respectively. Marginal structural Cox models were used to examine hazard ratios (HRs) of mortality and hospital admission due to lung cancer following air pollution exposure, adjusting for potential confounders. The HRs of mortality due to lung cancer were 1.042 (95% confidence interval [CI]: 1.033-1.052), 1.032 (95% CI:1.024-1.041) and 1.052 (95% CI:1.041-1.063) for each 1 μg/m3 increase in PM2.5 , PM10 and NO2 , respectively. In addition, we observed statistically significant effects of PMs on hospital admission due to lung cancer. The HRs (95%CI) were 1.110 (1.027-1.201), 1.067 (1.020-1.115) and 1.079 (1.010-1.153) for every 1 μg/m3 increase in PM2.5 , PM10 , PM10-2.5 , respectively. Furthermore, we found larger effect estimates among the elderly and those who exercised more frequently. We provided the most comprehensive evidence of the potential causal links between two outcomes of lung cancer and long-term air pollution exposure. Relevant policies should be developed, with special attention to protecting the vulnerable groups of the population.

Climate co-benefits of VOC control policies in China based on a cross-scale approach

Volatile organic compounds (VOC) contributing to smog formation, have been an important indicator of atmospheric governance during China's "14th Five-Year Plan". VOC would be possibly incorporated into the scope of environmental protection tax, but previous studies have seldom explored impacts of VOC control policies at national and regional levels. Here, we design a national uniform VOC control policy, as well as two regionally differentiated policies based on regional disparities in PM2.5 concentrations and energy intensity by using a cross-scale dynamic computable general equilibrium (CGE) model. Our analysis is to assess the impacts of these policies on VOC, CO2, sulfur dioxide (SO2), nitrogen oxides (NOX), and PM2.5 emissions, air quality and environmental equity, and to estimate health benefits, policy costs and net benefits. We find that national and regionally differentiated VOC control policies generally lead to VOC emission reductions and generate co-benefits on emission reductions in CO2, SO2, NOX and PM2.5 at national and provincial levels. However, regional emission leakage exists due to differences in the provincial costs of VOC mitigation. The regionally differentiated VOC pricing policies are found to be more effective to enhance environmental equity than the uniform policy. In particular, the regionally differentiated VOC control policy based on provincial energy efficiency is found to be superior to other policies in terms of improve air quality. Furthermore, the human health benefits associated with VOC pricing policies would partially offset policy costs at both the national and regional levels. Our results suggest that policymakers would pay attention to developing regions with low energy efficiency which have the great emission reduction potential. Advanced producing technology and further end-of-pipe control measures to reduce non-combustion PM2.5 emissions are needed. VOC policy designed based on provincial energy efficiency provides great insights for environmental policy making to accomplish 2035 goal of building a Beautiful China.

Long-Term Exposure to PM2.5 and Mortality: A Cohort Study in China

We investigated the association of long-term exposure to atmospheric PM2.5 with non-accidental and cause-specific mortality in Yinzhou, China. From July 2015 to January 2018, a total of 29,564 individuals aged ≥ 40 years in Yinzhou were recruited for a prospective cohort study. We used the Cox proportional-hazards model to analyze the relationship of the 2-year average concentration of PM2.5 prior to the baseline with non-accidental and cause-specific mortality. The median PM2.5 concentration was 36.51 μg/m3 (range: 25.57-45.40 μg/m3). In model 4, the hazard ratios per 10 μg/m3 increment in PM2.5 were 1.25 (95%CI: 1.04-1.50) for non-accidental mortality and 1.38 (95%CI:1.02-1.86) for cardiovascular disease mortality. We observed no associations between PM2.5 and deaths from respiratory disease or cancer. In the subgroup analysis, interactions were observed between PM2.5 and age, as well as preventive measures on hazy days. The observed association between long-term exposure to atmospheric PM2.5 at a relatively moderate concentration and the risk of non-accidental and cardiovascular disease mortality among middle-aged and elderly Chinese adults could provide evidence for government decision-makers to revise environmental policies towards a more stringent standard.

Associations of long-term joint exposure to various ambient air pollutants with all-cause and cause-specific mortality: evidence from a large population-based cohort study

The association between long-term joint exposure to all kinds of ambient air pollutants and the risk of mortality is not known. Our study prospectively assessed the joint associations of various air pollutants with cause-specific and all-cause mortality risk and identified potential modifying factors affecting these associations. A total of 400,259 individuals aged 40-70 years were included in this study. Information on PM10, PM2.5-10, PM2.5, NO2, and NOx was collected. A weighted air pollution score was calculated to assess joint exposure to the above air pollutants. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models. During a median of 12.0 years (4,733,495 person-years) of follow-up, 21,612 deaths were recorded, including 7097 deaths from cardiovascular disease and 11,557 deaths from cancer. The adjusted HRs of all-cause mortality were 1.39 (95% CI: 1.29-1.50), 1.86 (95% CI: 1.63-2.13), 1.12 (95% CI: 1.10-1.14), and 1.04 (95% CI: 1.03-1.05) for every 10-ug/m3 increase in PM10, PM2.5, NO2, and NOx, respectively. The adjusted HRs associated with the air pollution score (the highest quintile versus the lowest quintile) were 1.24 (95% CI: 1.19-1.30) for all-cause mortality, 1.33 (95% CI: 1.23-1.43) for cardiovascular mortality, and 1.16 (95% CI: 1.09-1.23) for cancer mortality. Furthermore, we found that the air pollution score was associated with a linear dose-response increase in mortality risk (all P for linearity < 0.001). The findings highlight the importance of a comprehensive assessment of various air pollutants.

Individual and joint associations of long-term exposure to air pollutants and cardiopulmonary mortality: a 22-year cohort study in Northern China

Background

Evidence on the associations between long-term exposure to multiple air pollutants and cardiopulmonary mortality is limited, especially for developing regions with higher pollutant levels. We aimed to characterise the individual and joint (multi-pollutant) associations of long-term exposure to air pollutants with cardiopulmonary mortality, and to identify air pollutant that primarily contributes to the mortality risk.

Methods

We followed 37,442 participants with a mean age of 43.5 years in four cities in northern China (Tianjin, Shenyang, Taiyuan, and Rizhao) from January 1998 to December 2019. Annual particulate matter (PM) with diameters ≤2.5 μm (PM2.5), ≤10 μm (PM10), sulfur dioxide (SO2) and nitrogen dioxide (NO2) were estimated using daily average values from satellite-derived machine learning models and monitoring stations. Time-varying Cox proportional hazards model was used to evaluate the individual association between air pollutants and mortality from non-accidental causes, cardiovascular diseases (CVDs), non-malignant respiratory diseases (RDs) and lung cancer, accounting for demographic and socioeconomic factors. Effect modifications by age, sex, income and education level were also examined. Quantile-based g-Computation integrated with time-to-event data was additionally applied to evaluate the co-effects and the relative weight of contributions for air pollutants.

Findings

During 785,807 person-years of follow-up, 5812 (15.5%) died from non-accidental causes, among which 2932 (7.8%) were from all CVDs, 479 (1.3%) from non-malignant RDs, and 552 (1.4%) from lung cancer. Long-term exposure to PM10 (mean [baseline]: 136.5 μg/m3), PM2.5 (mean [baseline]: 70.2 μg/m3), SO2 (mean [baseline]: 113.0 μg/m3) and NO2 (mean [baseline]: 39.2 μg/m3) were adversely and consistently associated with all mortality outcomes. A 10 μg/m3 increase in PM2.5 was associated with higher mortality from non-accidental causes (hazard ratio 1.20; 95% confidence interval 1.17-1.23), CVDs (1.23; 1.19-1.28), non-malignant RDs (1.37; 1.25-1.49) and lung cancer (1.14; 1.05-1.23). A monotonically increasing curve with linear or supra-linear shape with no evidence of a threshold was observed for the exposure-response relationship of mortality with individual or joint exposure to air pollutants. PM2.5 consistently contributed most to the elevated mortality risks related to air pollutant mixture, followed by SO2 or PM10.

Interpretation

There was a strong and positive association of long-term individual and joint exposure to PM10, PM2.5, SO2, and NO2 with mortalities from non-accidental causes, CVDs, non-malignant RDs and lung cancer in high-exposure settings, with PM2.5 potentially being the main contributor. The shapes of associations were consistent with a linear or supra-linear exposure-response relationship, with no lower threshold observed within the range of concentrations in this study.

Funding

National Key Research and Development Program of China, the China Scholarship Council, the National Natural Science Foundation of China, Natural Science Foundation of Guangdong Province.

High-dimensional spatiotemporal visual analysis of the air quality in China

Air quality is a significant environmental issue among the Chinese people and even the global population, and it affects both human health and the Earth's long-term sustainability. In this study, we proposed a multiperspective, high-dimensional spatiotemporal data visualization and interactive analysis method, and we studied and analyzed the relationship between the air quality and several influencing factors, including meteorology, population, and economics. Six visualization methods were integrated in this study, each specifically designed and improved for visualization analysis purposes. To reveal the spatiotemporal distribution and potential impact of the air quality, we designed a comprehensive coupled visual interactive analysis approach visually express both high-dimensional and spatiotemporal attributes, reveal the overall situation and explain the relationship between attributes. We clarified the current spatiotemporal distribution, development trends, and influencing factors of the air quality in China through interactive visual analysis of a 25-dimensional dataset involving 31 Chinese provinces. We also verified the correctness and effectiveness of relevant policies and demonstrated the advantages of our method.

Association between long-term exposure to air pollution and the risk of incident laryngeal cancer: a longitudinal UK Biobank-based study

We assessed the association between long-term joint exposure to ambient air pollutants and the risk of laryngeal cancer and whether this risk was modified by genetic susceptibility. We used a multivariable Cox proportional hazards regression model to analyze data from UK Biobank to determine the relationship between long-term exposure to air pollutants-nitric oxide (NO), nitrogen dioxide (NO₂), and 2.5-µm and 10-µm particulate matter (PM_2.5 and PM₁₀) and the risk of laryngeal cancer. In multivariable-adjusted models, in model 3 and compared with the participants with lower quintile scores for air pollution, the participants with the highest quintile scores for air pollution had a higher laryngeal cancer risk. The observed association was more pronounced among the participants who were female, were smokers, had a systolic blood pressure equal to or greater than 120 mmHg, and had diabetes. Compared with the participants with a low GRS and the lowest quintile score for air pollution exposure, those with an intermediate GRS and the highest quintile score for air pollution exposure had a higher risk of laryngeal cancer. Long-term exposure to NO₂, NO, or PM_2.5, individually or jointly, was associated with a risk of incident laryngeal cancer, especially in the participants with an intermediate GRS.

Long-term ambient air pollution exposure and cardio-respiratory disease in China: findings from a prospective cohort study

BACKGROUND

Existing evidence on long-term ambient air pollution (AAP) exposure and risk of cardio-respiratory diseases in China is mainly on mortality, and based on area average concentrations from fixed-site monitors for individual exposures. Substantial uncertainty persists, therefore, about the shape and strength of the relationship when assessed using more personalised individual exposure data. We aimed to examine the relationships between AAP exposure and risk of cardio-respiratory diseases using predicted local levels of AAP.

METHODS

A prospective study included 50,407 participants aged 30-79 years from Suzhou, China, with concentrations of nitrogen dioxide (NO2), sulphur dioxide (SO2), fine (PM2.5), and inhalable (PM10) particulate matter, ozone (O3) and carbon monoxide (CO) and incident cases of cardiovascular disease (CVD) (n = 2,563) and respiratory disease (n = 1,764) recorded during 2013-2015. Cox regression models with time-dependent covariates were used to estimate adjusted hazard ratios (HRs) for diseases associated with local-level concentrations of AAP exposure, estimated using Bayesian spatio-temporal modelling.

RESULTS

The study period of 2013-2015 included a total of 135,199 person-years of follow-up for CVD. There was a positive association of AAP, particularly SO2 and O3, with risk of major cardiovascular and respiratory diseases. Each 10 µg/m3 increase in SO2 was associated with adjusted hazard ratios (HRs) of 1.07 (95% CI: 1.02, 1.12) for CVD, 1.25 (1.08, 1.44) for COPD and 1.12 (1.02, 1.23) for pneumonia. Similarly, each 10 µg/m3 increase in O3 was associated with adjusted HR of 1.02 (1.01, 1.03) for CVD, 1.03 (1.02, 1.05) for all stroke, and 1.04 (1.02, 1.06) for pneumonia.

CONCLUSIONS

Among adults in urban China, long-term exposure to ambient air pollution is associated with a higher risk of cardio-respiratory disease.

Health risk assessment for particulate matter: application of AirQ+ model in the northern Caribbean region of Colombia

Air pollution is considered the world's most important environmental and public health risk. The annual exposure for particulate matter (PM) in the northern Caribbean region of Colombia between 2011 and 2019 was determined using PM records from 25 monitoring stations located within the area. The impact of exposure to particulate matter was assessed through the updated Global Burden of Disease health risk functions using the AirQ+ model for mortality attributable to acute lower respiratory disease (in children ≤ 4 years); mortality in adults aged > 18 years old attributable to chronic obstructive pulmonary disease, ischaemic heart disease, lung cancer, and stroke; and all-cause post-neonatal infant mortality. The proportions of the prevalence of bronchitis in children and the incidence of chronic bronchitis in adults attributable to PM exposure were also estimated for the population at risk. Weather Research and Forecasting-California PUFF (WRF-CALPUFF) modeling systems were used to estimate the spatiotemporal trends and calculate mortality relative risk due to prolonged PM_2.5 exposure. Proportions of mortality attributable to long-term exposure to PM_2.5 were estimated to be around 11.6% of ALRI deaths in children ≤ 4 years of age, 16.1% for COPD, and 26.6% for IHD in adults. For LC and stroke, annual proportions attributable to PM exposure were estimated to be 9.1% and 18.9%, respectively. An estimated 738 deaths per year are directly attributed to particulate matter pollution. The highest number of deaths per year is recorded in the adult population over 18 years old with a mean of 401 events. The mean risk in terms of the prevalence of bronchitis attributable to air pollution in children was determined to be 109 per 100,000 inhabitants per year. The maximum RR values for mortality (up 1.95%) from long-term PM_2.5 exposure were predicted to correspond to regions downwind to the industrial zone.

Supplementary information

The online version contains supplementary material available at 10.1007/s11869-023-01304-5.

Cardiovascular Mortality, Habitual Exercise, and Particulate Matter 2.5 Exposure: A Longitudinal Cohort Study

INTRODUCTION

Habitual exercise may amplify the respiratory uptake of air pollutants in the lung, exacerbating the adverse effects of air pollution. However, it is unclear whether this can reduce the health benefits of habitual exercise (referred to as leisure-time exercise). Thus, the combined effects of habitual exercise and chronic exposure to ambient fine particulate matter 2.5 on cardiovascular mortality were examined among adults in Taiwan.

METHODS

A total of 384,128 adults were recruited between 2001 and 2016 and followed up to May 31, 2019. Participants' vital status was obtained by matching their unique identification numbers with records of cardiovascular death in the National Death Registry of Taiwan. A time-varying Cox regression model was used to analyze the data. Analyses were conducted in 2021.

RESULTS

Cardiovascular death risks were inversely associated with habitual exercise and positively associated with chronic exposure to particulate matter 2.5. The beneficial effects of habitual exercise on cardiovascular mortality were not modified by chronic exposure to particulate matter 2.5. Inactive participants with high particulate matter 2.5 exposure exhibited a 123% higher risk of cardiovascular death than high-exercise-group participants exposed to low levels of particulate matter 2.5 (95% CI=89, 163).

CONCLUSIONS

High level of habitual exercise combined with low exposure level of ambient particulate matter 2.5 is associated with the lowest risk of cardiovascular death. A higher level of habitual exercise is associated with a lower risk of cardiovascular death at all levels of particulate matter 2.5 exposure studied. The results indicate that habitual exercise is a safe health promotion strategy even for people residing in relatively polluted regions.

Effects of transboundary PM2.5 transported from China on the regional PM2.5 concentrations in South Korea: A spatial panel-data analysis

This study identifies causal links between a high-PM2.5 episode in Korea and air pollutants originating from China during a high-PM2.5 episode that occurred in Korea between February 23 and March 12, 2019. Datasets on ground-based PM2.5 levels in Korea and China, airflows from the back-trajectory models, and satellite images were investigated, and long-range transboundary transport (LRTT) effects were statistically analyzed using spatial panel-data models. The findings are: 1) visual presentations of the observed PM2.5 concentration in China and Korea, back-trajectory air flows, and satellite images from the Moderate Resolution Imaging Spectroradiometer Aerosol Optical Depth and the Copernicus Atmosphere Monitoring Service clearly show that transboundary air pollutants from China affect PM2.5 concentration in Korea; 2) the effect of LRTT from China is likely to intensify under certain meteorological conditions, such as westerly winds from China to Korea, the formation of high pressure in China and low pressure in Korea, relatively high temperature, and stagnant air flow in Korea; 3) the results from the spatial panel-data models provide statistical evidence of the positive effect of LRTT from China on increasing local PM2.5 concentration in Korea. The nationwide average LRTT contributions to PM2.5 concentration in Korea are 38.4%, while regional contributions are 41.3% for the Seoul Metropolitan Area, 38.6% for the northwest region, and 27.5% for the southeast regions in Korea, indicating the greatest impact on the Seoul Metropolitan Area.

The efforts of China to combat air pollution during the period of 2015-2018: A case study assessing the environmental, health and economic benefits in the Beijing-Tianjin-Hebei and surrounding "2 + 26" regions

During the period of 2015-2018, Chinese government had made great efforts to mitigate air pollutants, such as air quality monitoring, energy structure adjustment, and pollutant emission reduction from industry, transportation and household sectors. With the special investment of 152 billion Chinese Yuan (CNY) in the Beijing-Tianjin-Hebei (BTH) and surrounding "2 + 26" regions, the annual local concentrations of PM_2.5, PM₁₀, SO₂ and NO₂ decreased from 77, 132, 38 and 46 μg/m³ to 60, 109, 20 and 43 μg/m³. It was estimated that the improvement in air quality avoided 27,021 (95 % CIs 12,548-39,738) premature deaths attributed to air pollution exposure based on an exposure-response function, including 45 %, 17 % and 15 % of cardiopulmonary, lung cancer and respiratory morality cases. Air pollution reduction was also effective in reducing work time loss, which reduced the total working time loss by 3.8 × 10⁷ (95 % CIs 1.8 × 10⁷-5.6 × 10⁷) h, and the per capita working time loss by 0.28 (95 % CIs 0.13-0.41) h/capita by 2018. From the economic aspect, air pollution control actions in those regions saved 95.6 (95 % CIs 44.2-141) billion CNY economic loss by using the value of statistical life (VSL). The total benefit-cost ratio was 63.7 % (95 % CIs 29.4 %-93.7 %). The cost-effectiveness in Beijing and Tianjin were relatively low due to the regional contribution from other cities of the air pollution transmission channel. Despite the uncertainties, the results clearly show the significance of the environmental, health and economic benefits of actions in the BTH and surrounding "2 + 26" regions for combating air pollution.

The Effects of COVID-19 Lockdown on Air Pollutant Concentrations across China: A Google Earth Engine-Based Analysis

To overcome the spread of the severe COVID-19 outbreak, various lockdown measures have been taken worldwide. China imposed the strictest home-quarantine measures during the COVID-19 outbreak in the year 2020. This provides a valuable opportunity to study the impact of anthropogenic emission reductions on air quality. Based on the GEE platform and satellite imagery, this study analyzed the changes in the concentrations of NO₂, O₃, CO, and SO₂ in the same season (1 February-1 May) before and after the epidemic control (2019-2021) for 16 typical representative cities of China. The results showed that NO₂ concentrations significantly decreased by around 20-24% for different types of metropolises, whereas O₃ increased for most of the studied metropolises, including approximately 7% in megacities and other major cities. Additionally, the concentrations of CO and SO₂ showed no statistically significant changes during the study intervals. The study also indicated strong variations in air pollutants among different geographic regions. In addition to the methods in this study, it is essential to include the differences in meteorological impact factors in the study to identify future references for air pollution reduction measures.

Etiology of lung cancer: Evidence from epidemiologic studies

Lung cancer is one of the leading causes of cancer incidence and mortality worldwide. While smoking, radon, air pollution, as well as occupational exposure to asbestos, diesel fumes, arsenic, beryllium, cadmium, chromium, nickel, and silica are well-established risk factors, many lung cancer cases cannot be explained by these known risk factors. Over the last two decades the incidence of adenocarcinoma has risen, and it now surpasses squamous cell carcinoma as the most common histologic subtype. This increase warrants new efforts to identify additional risk factors for specific lung cancer subtypes as well as a comprehensive review of current evidence from epidemiologic studies to inform future studies. Given the myriad exposures individuals experience in real-world settings, it is essential to investigate mixture effects from complex exposures and gene-environment interactions in relation to lung cancer and its subtypes.

Recent advances in small cell lung cancer: the future is now?

Small cell lung cancer is a relevant clinical issue as it is a highly malignant cancer, often diagnosed in advanced stage. Similarly to non-small cell lung cancer, tobacco smoking is currently the main risk factor. Its incidence, at least in males, has declined over the past decades, due to the worldwide decreased percentage of active smokers. The typical small cells of this tumor type are characterized by a high Proliferation Index, chromosomal deletions such as 3p(14-23) involving the tumor-suppressor gene FHIT, alterations of the MYC or Notch family proteins and the frequent expression of neuroendocrine markers. The combination of thoracic radiotherapy and chemotherapy is the standard treatment for limited stage disease, while platinum-based chemotherapy is the most effective choice for extensive stage disease. Unfortunately, whatever chemotherapy is used, the results are disappointing. No regimen has proved to be effective in the long run, indeed small cell lung cancer rapidly progresses after a frequent initial strong response, and the mortality rate remains still high. The advent of immunotherapy is actually changing the landscape in oncology. As well as in other cancers, recent trials have demonstrated the efficacy of the combination of immune checkpoint inhibitors and chemotherapy, opening new perspectives for the future of our patients.

Deciphering the impact of urban built environment density on respiratory health using a quasi-cohort analysis of 5495 non-smoking lung cancer cases

INTRODUCTION

Lung cancer is a major health concern and is influenced by air pollution, which can be affected by the density of urban built environment. The spatiotemporal impact of urban density on lung cancer incidence remains unclear, especially at the sub-city level. We aimed to determine cumulative effect of community-level density attributes of the built environment on lung cancer incidence in high-density urban areas.

METHODS

We selected 78 communities in the central city of Shanghai, China as the study site; communities included in the analysis had an averaged population density of 313 residents per hectare. Using data from the city cancer surveillance system, an age-period-cohort analysis of lung cancer incidence was performed over a five-year period (2009-2013), with a total of 5495 non-smoking/non-secondhand smoking exposure lung cancer cases. Community-level density measures included the density of road network, facilities, buildings, green spaces, and land use mixture.

RESULTS

In multivariate models, built environment density and the exposure time duration had an interactive effect on lung cancer incidence. Lung cancer incidence of birth cohorts was associated with road density and building coverage across communities, with a relative risk of 1·142 (95 % CI: 1·056-1·234, P = 0·001) and 1·090 (95 % CI: 1·053-1·128, P < 0·001) at the baseline year (2009), respectively. The relative risk increased exponentially with the exposure time duration. As for the change in lung cancer incidence over the five-year period, lung cancer incidence of birth cohorts tended to increase faster in communities with a higher road density and building coverage.

CONCLUSION

Urban planning policies that improve road network design and building layout could be important strategies to reduce lung cancer incidence in high-density urban areas.

Effects of air pollution on cardiovascular health in patients with type 2 diabetes mellitus: Evidence from a large tertiary hospital in Shandong Province, China

Air pollution has posed serious threats to human health. Based on the microdata of a large tertiary hospital in Shandong Province from 2016 to 2021, combined with the macro data such as air quality monitoring data, meteorological data, and city-level regional socio-economic data, this paper empirically tests the impact of air pollution instrumented by thermal inversions on the cardiovascular health of patients with type 2 diabetes mellitus (T2DM) and its group differences. The results show that: (1) Air pollution has a negative impact on the cardiovascular health of patients with T2DM, that is, the cardiovascular health of patients with T2DM will decline in regions with high air pollution; (2) The impact of air pollution on cardiovascular health in T2DM patients is heterogeneous, with males and older patients bearing greater air pollution health losses; (3) From the perspective of the external environment, the negative effects of environmental pollution on patients' health were significantly reduced in areas with higher environmental regulation intensity and better public health conditions, indicating the necessity of strengthening environmental governance and increasing public health expenditure.

The association between outdoor air pollution and lung cancer risk in seven eastern metropolises of China: Trends in 2006-2014 and sex differences

There is a positive association between air pollution and lung cancer burden. This study aims to identify and examine lung cancer risks and mortality burdens associated with air pollutants, including PM₁₀, NO₂ and SO₂, in seven eastern metropolises of China. The study population comprised a population from seven eastern metropolises of China. The yearly average values (YAV, μg/m³) of the PM₁₀, NO₂ and SO₂ levels were extracted from China Statistical Yearbook (CSYB) for each selected city from 2006 to 2014. Data collected in the China Cancer Registry Annual Report (CCRAR) provide lung cancer incidence and mortality information. A two-level normal random intercept regression model was adopted to analyze the association between the lung cancer rates and individual air pollutant concentration within a five-year moving window of past exposure. The yearly average values of PM10, SO2 and NO2 significantly decreased from 2006 to 2014. Consistently, the male age-adjusted incidence rate (MAIR) and male age-adjusted mortality rate (MAMR) decreased significantly from 2006 to 2014.Air pollutants have a lag effect on lung cancer incidence and mortality for 2-3 years. NO2 has the significant association with MAIR (RR=1.57, 95% CI: 1.19-2.05, p=0.002), MAMR (RR=1.70, 95% CI: 1.32-2.18, p=0.0002) and female age-adjusted mortality rate (FAMR) (RR=1.27, 95% CI: 1.08-1.49, p=0.003). Our findings suggested that air pollutants may be related to the occurrence and mortality of lung cancer. NO2 was significantly associated with the risk of lung cancer, followed by SO2. Air pollutants have the strongest lag effect on the incidence and mortality of lung cancer within 2-3 years.

Environmental quality, healthcare and research and development in Saudi Arabia

While global warming and climate change associated with increasing carbon dioxide are widely seen to be one of the most serious worldwide dangers to population health, little is known regarding "how" country alters the linkage between increasing CO2 emissions and population health outcomes. Current literature on the health effects of CO2 emissions recommends various factors that may establish a more robust link, including health expenditure and research and development. Therefore, the purpose of this inquiry is to examine the effectiveness of health expenditure and R&D in improving health outcomes through reducing CO2 emissions. Using data for Saudi Arabia over the period 2000-2018, the dynamic ordinary least squares (DOLS) technique shows that (i) health and R&D expenditures decrease infant mortality and increase life expectancy; (ii) health and R&D expenditures reduce CO2 emissions in all the estimated models; (iii) health and R&D expenditures can improve health outcomes through reducing CO2 emissions; and (iv) health and R&D expenditures have both direct and indirect effect on health outcomes. Policy implications and limitations are also discussed.

Effect of ambient O3 on mortality due to circulatory and respiratory diseases in a high latitude city of northeast China

In recent years, O₃ pollution had been worsening in China and became a major challenge for human health. To evaluate the O₃ effects on circulatory and respiratory mortality in Harbin, a high latitude city of northeast China, we applied a time-series study from 2014 to 2016. After collecting data and adjusting for the effects of confounders, we built the generalized additive model to assess the associations between O₃ and mortality at different lag days. The results showed that an interquartile-range (IQR) increase in O₃ concentration corresponded to excess risk (ER) of 2.00% (95%CI: - 0.25-4.30%) for circulatory mortality at lag 0 and 8.02% (95%CI: 4.18-12.01%) for respiratory mortality at lag 2 days in the single-pollutant model. Stratified analysis showed that O₃ had a greater effect on females than on males. The effect of O₃ exposure on circulatory mortality was stronger during the warm period, while the opposite trend was founded for respiratory mortality. The sensitivity analysis showed that the effects of O₃ were relatively independent and the major results were robust.

Lowering mortality risks in urban areas by containing atmospheric pollution

OBJECTIVES

Although studies collectively examining the traffic and residential heat pollutant emissions are abundant, research investigations dedicated to Cyprus are scarce. This investigation has simulated the levels of air pollutants, namely, CO, NO_x, PM_2.5, and PM₁₀ and reconciled them with actual air quality measurements in Nicosia, Cyprus, during a 9-month period at an hourly resolution. To this end, several scenarios and cases were formulated to tackle emissions and minimise human mortality risks in the city.

METHODS

The GRAL dispersion model was used to project pollution levels. Nine different traffic scenarios were devised to estimate variations in concentration of PM_2.5 and NO_x under various policies, such as banning diesel passenger vehicles (PV), light duty vehicles (LDV), non-Euro 6 standards vehicles, stringent speed limits and a ubiquitous roll-out of electric passenger vehicles. Moreover, 4 distinct cases were analysed to year 2030 considering a fluctuation in traffic of ±20% whereas all vehicles conform to Euro 6 standards. Three additional policies examined the prohibition of diesel PV and LDV, 80% electric PV and outlawing fireplaces. Drawing on the findings of these scenarios and cases, the total cardiovascular and respiratory mortality rates at the capital of Cyprus, Nicosia, were deduced.

RESULTS

The most promising scenario in terms of curbing emissions was to ban non-Euro 6 vehicles and diesel PV and LDV which could contain average NO_x concentration, in Nicosia, from 52.9 μg/m³ to 15.0 μg/m³. If this policy were to be implemented, it could have saved 70% of the premature deaths tied to NO_x emissions. For particulate matter, banning fireplaces and abandoning non-Euro 6 vehicles could lower average concentrations from 18.3 μg/m³ to 13.1 μg/m³, saving at least 30% of the people poised to lose their lives from particulate matter risks.

CONCLUSION

Traffic and residential heat policies are not easy to implement. However, our study has demonstrated that the most effective policies for curbing NO_x emissions would be to ensure that all vehicles abide with the Euro 6 standards and, concurrently, ban diesel passenger and light duty vehicles. Lastly, phasing out domestic fireplaces appears to be the most promising solution for containing particulate matter, in 2030.

COVID-19 induced restriction in developing countries and its impacts on pollution load: case study of Lagos mega city

Sudden outbreak of COVID-19 pandemic globally in 2020 warranted urgent course of actions to guide against its escalation. The first and immediate measure adopted by several nations was the imposition of restriction on transport, industrial, commercial and social activities; and this step has thus, provided a platform for the impact assessment of the restrictions on ambient air quality, especially in developing nations such as Nigeria. The levels of four criteria air pollutants (PM_2.5, SO₂, NO₂, and PM₁₀) in ambient air of Lagos city before, during and after the restriction periods were compared to establish the extent of change caused by the restrictions. The results revealed a decline of 74.0, 79.7, 55.0 and 58.5% in the levels of SO₂, NO₂, PM_2.5, and PM₁₀, respectively during the lockdown period. The results also revealed that, despite the huge reduction in the atmospheric emissions witnessed during lockdown period, air quality within the region was still poor, as the levels of most of the pollutants were above the recommended limits. These findings suggested that apart from the restricted activities, there are other air pollution sources within the city which increased the pollution load in the ambient air. Conclusively, while the restriction led to untold economic hardship, it equally enhanced quality of ambient air. Cleaner technology is advocated to ensure reduction in the consumption of fossil fuel instead of the common practice of end-of-pipe technology, for environmental sustainability.

Spatial heterogeneity of human lifespan in relation to living environment and socio-economic polarization: a case study in the Beijing-Tianjin-Hebei region, China

The spatial heterogeneity and influence factors of public lifespan have been reported worldwide at the national level or typical longevous areas. However, few sub-national studies considering the living environment and socio-economic level together have been explored in the imbalanced developed region with a huge population base and deteriorated air quality. In this paper, spatial heterogeneity of lifespan integrating environment and socio-economic influence factors was investigated in the Beijing-Tianjin-Hebei (BTH) region of China using geographically weighted regression (GWR). Five indicators were constructed to determine the lifespan based on the three national censuses (1990-2010) in the BTH region. The results showed that the areas with higher CH (centenarians per 100,000 inhabitants) and centenarity index (CI) exhibited changing distribution in the BTH region, whereas those with lower CH and CI and extreme value of the ultra-octogenarian index (UOI) and LI (> 90/ > 65) maintained a relatively stable feature through time. But as lifespan indicators increase overall, the differences between the counties/districts widen. Furthermore, remarkable spatial heterogeneity was detected for the associations between the significant environmental and socio-economic variables and lifespan indicators. Although the natural geographic condition (altitude) still exhibited a negative influence on the longevity of the population, the socio-economic factors (GDP_pc and income level) showed a more dominant influence on the extension of the elderly and longevity population. Correspondingly, the widened unbalance of population lifespan (UOI, LI, CH) was considered closely related to the socio-economic polarization, and the adverse effects of air pollution on life expectancy at birth (LEB) have also emerged. To further improve the overall lifespan level and narrow the lifespan gap in the BTH region, future work on cleaner air and more balanced development is still needed.

Human health risk assessment of PM2.5-bound heavy metal of anthropogenic sources in the Khon Kaen Province of Northeast Thailand

The study aimed to assess the human health risk of PM_2.5-bound heavy metals from anthropogenic sources in Khon Kaen Province, Thailand between December 2020 and February 2021. According to the findings, the geometric mean concentration of PM_2.5 in the university area, residential area, industrial zone, and the agricultural zone was 32.78 μg/m³, 50.25 μg/m³, 44.48 μg/m³, and 29.53 μg/m³, respectively. The results showed that the estimated human health risk assessment, in terms of non-carcinogenic risks among children and adults in an urban area (residential and university), industrial zone, and the agricultural area, was of hazard index (HI) value of >1.0 indicating a greater chance of chronic effects occurring. This study showed that exposure to PM_2.5-bound heavy metal may increase the likelihood that lasting effects will result in a very high carcinogenic risk (CR) in children in residential areas, and an industrial zone with total carcinogenic risk (TCR) values of 0.23×101, and 0.12×101, respectively while resulting in a high TCR of 3.34×10−2 and 4.11×10−2 within the university areas and agricultural zone, respectively. In addition, health risk assessments among adults demonstrate high TCR values of 4.40×10−1 (residential area), 2.28×10−1 (industrial zone), and 7.70×10−3 (agricultural zone), thus indicating a potential health risk to adults living in these areas while the university area was very low effects on carcinogenic risk (CR≤10−8) for adults. Therefore, lowering the risk of exposure to PM_2.5 via the respiratory tract, for example, wearing a mask outside is a very effective self-defense strategy for people within and around the study site. This data study strongly supports the implementation of the air pollutant emission source reduction measures control and health surveillance.

Impact of Environmental Quality on Health Outcomes in Saudi Arabia: Does Research and Development Matter?

Recent literature on the health impacts of CO₂ emissions suggests a variety of factors that may establish a more robust link. However, no previous study has explored the role of research and development (R&D) in explaining the nexus between CO₂ emissions and health outcomes. Using data for Saudi Arabia over the period 2000–2018, this paper investigates the ability of R&D (expenditures and environmentally related R&D) to reduce the incidence of emissions on population health outcomes, particularly infant mortality and life expectancy. We find (i) negative impacts of CO₂ emissions on health outcomes; (ii) R&D expenditures have a weak positive impact on health outcomes; (iii) additionally to their direct effects on health outcomes, R&D expenditures remarkably enhanced health outcomes through reducing per capita CO₂ emissions; (iv) R&D expenditures interact with CO₂ from electricity and heat production and from electricity and heat production to negatively influence health outcomes. Similarly, environmentally related R&D, measured by patents environmental-related technologies, interacts with per capita CO₂ emissions to negatively influence health outcomes. To address these negative impacts, we calculated the corresponding R&D thresholds. Policymakers in Saudi Arabia are therefore called to give more and more incentives for R&D to reduce emissions and then improve population health outcomes.

Long-term Exposure to Fine Particulate Matter and Mortality A Longitudinal Cohort Study of 400,459 Adults

BACKGROUND

Cohort studies on the association between long-term exposure to fine particulate matter (PM2.5) and mortality have been well established for America and Europe, but limited and inconsistent in Asia with much higher air pollution. This study aims to investigate the associations between ambient PM2.5 and all-cause and cause-specific mortality over a period of rising and then declining PM2.5.

METHODS

We enrolled a total of 400,459 adults from an open cohort between 2001 and 2016, and followed them up until 31 May 2019. We obtained mortality data from the National Death Registry maintained by the Ministry of Health and Welfare in Taiwan. We estimated ambient PM2.5 exposures using a satellite-based spatiotemporal model. We performed a Cox regression model with time-dependent covariates to investigate the associations of PM2.5 with deaths from all causes and specific causes.

RESULTS

This study identified 14,627 deaths and had a total of 5 million person-years of follow-up. Each 10 µg/m3 increase in PM2.5 was associated with an increased hazard risk of 29% (95% confidence interval: 24%-35%) in all-cause mortality. Risk of death increased by 30% for natural causes, 20% for cancer, 42% for cardiovascular disease (CVD) causes, and 53% for influenza and pneumonia causes, for each 10 µg/m3 increase in PM2.5. Sensitivity analyses generally yielded similar results.

CONCLUSION

Long-term exposure to ambient PM2.5 was associated with increased risks of all-cause mortality and deaths from cancers, natural causes, CVD, and influenza and pneumonia. Longitudinal study design should be encouraged for air pollution epidemiologic investigation.

Exploring the Spatiotemporal Evolution and Socioeconomic Determinants of PM2.5 Distribution and Its Hierarchical Management Policies in 366 Chinese Cities

From 2013 to 2017, progress has been made by implementing the Air Pollution Prevention and Control Action Plan. Under the background of the 3 Year Action Plan to Fight Air Pollution (2018–2020), the pollution status of PM2.5, a typical air pollutant, has been the focus of continuous attention. The spatiotemporal specificity of PM2.5 pollution in the Chinese urban atmospheric environment from 2018 to 2020 can be summarized to help conclude and evaluate the phased results of the battle against air pollution, and further, contemplate the governance measures during the period of the 14th Five-Year Plan (2021–2025). Based on PM2.5 data from 2018 to 2020 and taking 366 cities across China as research objects, this study found that PM2.5 pollution has improved year by year from 2018 to 2020, and that the heavily polluted areas were southwest Xinjiang and North China. The number of cities with a PM2.5 concentration in the range of 25–35 μg/m³ increased from 34 in 2018 to 86 in 2019 and 99 in 2020. Moreover, the spatial variation of the PM2.5 gravity center was not significant. Concretely, PM2.5 pollution in 2018 was more serious in the first and fourth quarters, and the shift of the pollution's gravity center from the first quarter to the fourth quarter was small. Global autocorrelation indicated that the space was positively correlated and had strong spatial aggregation. Local Moran's I and Local Geti's G were applied to identify hotspots with a high degree of aggregation. Integrating national population density, hotspots were classified into four areas: the Beijing–Tianjin–Hebei region, the Fenwei Plain, the Yangtze River Delta, and the surrounding areas were selected as the key hotspots for further geographic weighted regression analysis in 2018. The influence degree of each factor on the average annual PM2.5 concentration declined in the following order: (1) the proportion of secondary industry in the GDP, (2) the ownership of civilian vehicles, (3) the annual grain planting area, (4) the annual average population, (5) the urban construction land area, (6) the green space area, and (7) the per capita GDP. Finally, combined with the spatiotemporal distribution of PM2.5, specific suggestions were provided for the classified key hotspots (Areas A, B, and C), to provide preliminary ideas and countermeasures for PM2.5 control in deep-water areas in the 14th Five-Year Plan.

A novel multi-pollutant space-time learning network for air pollution inference

Detailed information about air pollution in space and time is essential to manage risks to public health. In this paper we propose a multi-pollutant space-time learning network (Multi-AP learning network), which estimates pixel-wise (grid-level) concentrations of multiple air pollutant species based on fixed-station measurements and multi-source urban features, including land use information, traffic data, and meteorological conditions. We infer concentrations of multiple pollutants within one integrated learning network, which is applied to and evaluated on a case study in Chengdu (4900 km², 26 April - 12 June 2019), where air pollutant (PM_2.5, PM₁₀ and O₃) measurements from 40 monitoring sites are used to train the network to estimate pollutant concentrations in 4900 grid-cells (1 km²). The Multi-AP learning network allows us to estimate highly-resolved (1 km × 1 km, hourly) air pollution maps based on pollutant measurements which cover less than 1% of the grid-cells with better accuracy compared to other approaches, and with significant computational efficiency improvements. The time-cost is 1/3 of the time-cost of modelling each pollutant individually. Furthermore, we evaluate the relative importance of features and find that the meteorological feature set is the most important followed the land use features. The proposed Multi-AP method could be used to estimate air pollution exposure across a city using a limited set of air pollution monitoring sites.

Spatial-Temporal Evolution of Health Impact and Economic Loss upon Exposure to PM2.5 in China

Exposure to PM_2.5 can seriously endanger public health. Policies for controlling PM_2.5 need to consider health hazards under different circumstances. Unlike most studies on the concentration, distribution, and influencing factors of PM_2.5, the present study focuses on the impact of PM_2.5 on human health. We analysed the spatial-temporal evolution of health impact and economic loss caused by PM_2.5 exposure using the log-linear exposure-response function and benefit transfer method. The results indicate that the number of people affected by PM_2.5 pollution fluctuated and began to decline after reaching a peak in 2014, benefiting from the Air Pollution Prevention and Control Action Plan. Regarding the total economic loss, the temporal pattern continued to rise until 2014 and then declined, with an annual mean of 86,886.94 million USD, accounting for 1.71% of China’s GDP. For the spatial pattern, the health impact and economic loss show a strong spatial correlation and remarkable polarisation phenomena, with high values in East China, North China, Central China, and South China, but low values in Southwest China, Northwest China, and Northeast China. The spatial-temporal characterisation of PM_2.5 health hazards is visualised and analysed accordingly, which can provide a reference for more comprehensive and effective policy decisions.

Spatial Distribution of PM2.5-Related Premature Mortality in China

PM2.5 is a major component of air pollution in China and has a serious threat to public health. It is very important to quantify spatial characteristics of the health effects caused by outdoor PM2.5 exposure. This study analyzed the spatial distribution of PM2.5 concentration (45.9 μg/m3 national average in 2016) and premature mortality attributed to PM2.5 in cities at the prefectural level and above in China in 2016. Using the Global Exposure Mortality Model (GEMM), the total premature mortality in China was estimated to be 1.55 million persons, and the per capita mortality was 11.2 per 10,000 persons in the year 2016, resulting in higher estimates compared to the integrated exposure-response model. We assessed the premature mortality attributed to PM2.5 through common diseases, including ischemic heart disease (IHD), cerebrovascular disease (CEV), chronic obstructive pulmonary disease (COPD), lung cancer (LC), and lower respiratory infections (LRI). The premature mortality due to IHD and CEV accounted for 68.5% of the total mortality, and the per capita mortality (per 10,000 persons) for all ages due to IHD was 3.86, the highest among diseases. For the spatial distribution of disease-specific premature mortality, the top two highest absolute numbers of premature mortality associated with IHD, CEV, LC, and LRI, respectively, were found in Chongqing and Beijing. In 338 cities of China, we have found a significant positive spatial autocorrelation of per capita premature mortality, indicating the necessity of coordinated regional governance for an efficient control of PM2.5.

Research trends in the field of ambient air quality monitoring and management in South Africa: A bibliometric review

Air pollution is a leading environmental-health challenge facing the world today. Besides, the emergency of the COVID-19 pandemic has also put some spotlight on issues related to air pollution as both attack the same human respiratory organs. The purpose of this study was to provide an overview of research performance, trends and evolution in the field of ambient air quality monitoring and management in South Africa over the last decade (2010-2021) through the application of a bibliometric approach and a data mining software VOSViewer. Findings were that there has been a steady increase in the number of ambient air quality monitoring and management publications per year. Over the period under review, 2014 contributed 14 % while 2020 contributed 27 % of the total publications. Also, the study established that throughout the period South African scientist collaborated extensively with scientists from Finland, the United States of America, France, and Switzerland. Besides raising awareness levels in the field, the increase in studies can also assist policy formulation and development. In the meantime, the South African National government has also put in place several mitigation strategies to reduce emissions for example the enactment of ambient air quality guidelines.

Research on the Temporal and Spatial Characteristics of Air Pollutants in Sichuan Basin

Sichuan Basin is one of the most densely populated areas in China and the world. Human activities have great impact on the air quality. In order to understand the characteristics of overall air pollutants in Sichuan Basin in recent years, we analyzed the concentrations of six air pollutants monitored in 22 cities during the period from January 2015 to December 2020. During the study period, the annual average concentrations of CO, NO2, SO2, PM2.5 and PM10 all showed a clear downward trend, while the ozone concentration was slowly increasing. The spatial patterns of CO and SO2 were similar. High-concentration areas were mainly located in the western plateau of Sichuan Basin, while the concentrations of NO2 and particulate matter were more prominent in the urban agglomerations inside the basin. During the study period, changes of the monthly average concentrations for pollutants (except for O3) conformed to the U-shaped pattern, with the highest in winter and the lowest in summer. In the southern cities of the basin, secondary sources had a higher contribution to the generation of fine particulate matter, while in large cities inside the basin, such as Chengdu and Chongqing, air pollution had a strong correlation with automobile exhaust emissions. The heavy pollution incidents observed in the winter of 2017 were mainly caused by the surrounding plateau terrain with typical stagnant weather conditions. This finding was also supported by the backward trajectory analysis, which showed that the air masses arrived in Chengdu were mainly from the western plateau area of the basin. The results of this study will provide a basis for the government to take measures to improve the air quality in Sichuan Basin.

The prospective effects of long-term exposure to ambient PM2.5 and constituents on mortality in rural East China

Few cohort studies explored the associations of long-term exposure to ambient fine particulate matter with an aerodynamic diameter of 2.5 μm or less (PM2.5) and its chemical constituents with mortality risk in rural China. We conducted a 12-year prospective study of 28,793 adults in rural Deqing, China from 2006 to 2018. Annual mean PM2.5 and its constituents, including black carbon (BC), organic carbon (OC), ammonium (NH4+), nitrate (NO3-), sulfate (SO42-), and soil dust were measured at participants' addresses at enrollment from a satellite-based exposure predicting model. Cox proportional hazard model was used to estimate hazard ratios (HRs) and 95% confidence intervals (95%CIs) of long-term exposure to PM2.5 for mortality. A total of 1960 deaths were identified during the follow-up. We found PM2.5, BC, OC, NH4+, NO3-, and SO42- were significantly associated with an increased risk of non-accidental mortality. The HR for non-accidental mortality was 1.17 (95%CI: 1.07, 1.28) for each 10 μg/m3 increase in PM2.5. As for constituents, the strongest association was found for BC (HR = 1.21, 95%CI: 1.11, 1.33), followed by NO3-, NH4+, SO42-, and OC (HR = 1.14-1.17 per interquartile range). A non-linear relationship was found between PM2.5 and non-accidental mortality. Similar associations were found for cardio-cerebrovascular and cancer mortality. Associations were stronger among men and ever smokers. Conclusively, we found long-term exposure to ambient PM2.5 and its chemical constituents (especially BC and NO3-) increased mortality risk. Our results suggested the importance of adopting effective targeted emission control to improve air quality for health protection in rural East China.

AQI time series prediction based on a hybrid data decomposition and echo state networks

A hybrid AQI time series prediction model is proposed based on EWT-SE-VMD secondary decomposition, ICA (imperialist competitive algorithm) feature selection, and ESN (echo state network) neural network. Firstly, EWT (empirical wavelet transform) and VMD (variational mode decomposition) are used to decompose the original AQI time series into several stable and reliable subseries. Then, the ICA is used to select features of the above subseries for the ESN prediction model. Finally, the optimized feature variables are put into the ESN deep network to establish a prediction model of each AQI subseries and obtain the future AQI index. According to the experimental results of the daily AQI series in Beijing, Tianjin, and Shijiazhuang, we find that (a) among all decomposition methods, the proposed secondary decomposition method (EWT-SE-VMD) performs best in processing data; (b) it is proved that the proposed hybrid model has broad application prospect and research value in the AQI prediction field.

Health and economic benefits of clean air policies in China: A case study for Beijing-Tianjin-Hebei region

Exposure to PM_2.5 is associated with many adverse health effects, leading to additional social costs. The Blue Sky Protection Campaign (BSPC) has been implemented in 2018 in the Beijing-Tianjin-Hebei (BTH) area to control air pollution. This study assesses PM_2.5-related health and economic benefits of the BSPC in the BTH region. Results show that by 2020, PM_2.5 reduction can avoid 3561 thousand morbidity cases (equivalent to a 24% reduction in the 2020 baseline scenario) and 24 thousand premature deaths (12%) in the BTH region, with the majority benefit in Hebei. By 2030, the avoided morbidity and mortality cases will be 2943 (18%) thousand and 20 (9%) thousand, respectively. PM_2.5 reductions are highly effective in reducing work time loss, which will decrease the total annual work time by 1.7 × 10⁸ h (24%) in the BTH region by 2020. From the economic aspect, the reduced PM_2.5 concentration will save 30 million USD (25%) health expenditures and avoid 60 billion USD (13%) economic loss by using the value of statistical life (VSL) by 2020. In 2030, the health expenditures and economic loss will also decrease significantly, with 17 million USD (18%) and 63 billion USD (10%), respectively, in the BTH region. Besides, the economic benefits far exceed the policy costs of the BSPC, and the Δ benefit/Δ cost ratios of Beijing are significantly higher than those of Hebei. The BSPC in BTH has significant positive health and economic impacts. This study can provide a basis for future PM_2.5-related health risk studies at an urban level in China.

The Role of Respiratory Microbiota in Lung Cancer

Recently, the impact of microorganisms on tumor growth and metastasis has attracted great attention. The pathogenesis and progression of lung cancer are related to an increase in respiratory bacterial load as well as changes in the bacterial community because the microbiota affects tumors in many ways, including canceration, metastasis, angiogenesis, and treatment. The microbiota may increase tumor susceptibility by altering metabolism and immune responses, promoting inflammation, and increasing toxic effects. The microbiota can regulate tumor metastasis by altering multiple cell signaling pathways and participate in tumor angiogenesis through vascular endothelial growth factors (VEGF), endothelial cells (ECs), inflammatory factors and inflammatory cells. Tumor angiogenesis not only maintains tumor growth at the primary site but also promotes tumor metastasis and invasion. Therefore, angiogenesis is an important mediator of the interaction between microorganisms and tumors. The microbiota also plays a part in antitumor therapy. Alteration of the microbiota caused by antibiotics can regulate tumor growth and metastasis. Moreover, the microbiota also influences the efficacy and toxicity of tumor immunotherapy and chemotherapy. Finally, the effects of air pollution, a risk factor for lung cancer, on microorganisms and the possible role of respiratory microorganisms in the effects of air pollution on lung cancer are discussed.

Health and economic impacts from PM2.5 pollution transfer attributed to domestic trade in China: a provincial-level analysis

In recent years, severe air pollution has had a serious impact on the health and economy of residents and has attracted great attention. Due to the spatial separation between consumption and production, the transfer of PM_2.5 pollution and its health and economic effects caused by interprovincial trade have not been taken seriously. In this study, economic, atmospheric, and epidemiological models were combined to assess air pollution transfer and its health and economic impacts that are attributed to provincial trade in China. The analyses were performed under the PM_2.5 transfer scenario in which economically developed areas in eastern China transferred many health and economic impacts to inland areas through interprovincial trade in 2012. As a result of interprovincial trade, 1980 (95% CI 0, 4114) extra deaths and 208,000 (95% CI 74.5, 395.6) additional illnesses accrued, but 0.184 (95% CI 0.017, 0.372) billion USD of residents' economic loss was avoided in China. The results illustrate the serious impact of domestic trade on regional health and economics. It is necessary to comprehensively consider supply chains in designing policies to mitigate the negative health and economic impacts of air pollution across China.

Role of atmospheric particulate matter exposure in COVID-19 and other health risks in human: A review

Due to intense industrialization and urbanization, air pollution has become a serious global concern as a hazard to human health. Epidemiological studies found that exposure to atmospheric particulate matter (PM) causes severe health problems in human and significant damage to the physiological systems. In recent days, PM exposure could be related as a carrier for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus transmission and Coronavirus disease 2019 (COVID-19) infection. Hence, it is important to understand the adverse effects of PM in human health. This review aims to provide insights on the detrimental effects of PM in various human health problems including respiratory, circulatory, nervous, and immune system along with their possible toxicity mechanisms. Overall, this review highlights the potential relationship of PM with several life-limiting human diseases and their significance for better management strategies.

Association between atmospheric PM2.5 and daily outpatient visits for children's respiratory diseases in Lanzhou

The relationship between fine particulate matter (PM_2.5) and respiratory disease outcomes among children aged 0 to 14 years in Lanzhou, China, was evaluated. We utilized a generalized additive model linked by a quasi-Poisson distribution to examine the associations between PM_2.5 and paediatric respiratory outpatient visits for time lags of 0 up to 7 days, and stratified by gender, age, and season. Cases of respiratory disease in children were collected from 3 large hospitals for the years 2014-2017 and then linked with air pollutant concentrations from 4 air quality monitoring stations by date. We observed positive and significant associations between PM_2.5 and respiratory disease from the lag to lag 7, and from lag01 to lag07, with ER reaching the maximum value at lag07. For each 10 μg/m³ increase in PM_2.5 (lag07), the associated increment in respiratory diseases was 2.83% (95% CI 1.80%-3.86%). Males were more sensitive to the adverse effects, and the association was more significant in spring (from March to May) and winter (from December to the next February). Overall, the child group (age 3-6 years) demonstrated a higher risk of respiratory disease after PM_2.5 exposure. The associations between ambient PM_2.5 and respiratory hospital outpatients among young children became partially attenuated after the adjustment for gaseous pollutants in subgroups. The exposure-response curves were positive and generally nonlinear but flatted at concentrations over 60 μg/m³. This research found a significant association between ambient PM_2.5 levels and hospital outpatient visits in child with respiratory diseases in Lanzhou, China.

Association between PM10 and specific circulatory system diseases in China

Particulate matter (PM) has been proved to be a risk factor for the development of circulatory system diseases (CSDs) around the world. In this study, we collected daily air pollutants, emergency room (ER) visits for CSDs, and meteorological data from 2009 to 2012 in Beijing, China. After controlling for the long-term trend and eliminating the influence of confounding factors, the generalized additive model (GAM) was used to evaluate the short-term effects of PM10 on CSDs and cause-specific diseases. The results showed that for every 10 μg/m3 increase in PM10, the largest effect estimates in ER visits of total CSDs, arrhythmia, cerebrovascular diseases, high blood pressure, ischemic heart disease and other related diseases were 0.14% (95% CI: 0.06-0.23%), 0.37% (95% CI: - 0.23 to 0.97%), 0.20% (95% CI: 0.00-0.40%), 0.15% (95% CI: 0.02-0.27%), 0.18% (95% CI: 0.02-0.35%) and 0.35% (95% CI: - 0.04 to 0.79%), respectively. When NO2 or SO2 was added into the model, the effect estimates of PM10 were mostly attenuated, while in those models with PM2.5 added, the effect estimates of PM10 were mostly increased. Stratified analysis indicated that PM10 had a greater effect on males and the elderly.

Estimating ambient air pollutant levels in Suzhou through the SPDE approach with R-INLA

Spatio-temporal models of ambient air pollution can be used to predict pollutant levels across a geographical region. These predictions may then be used as estimates of exposure for individuals in analyses of the health effects of air pollution. Integrated nested Laplace approximations is a method for Bayesian inference, and a fast alternative to Markov chain Monte Carlo methods. It also facilitates the SPDE approach to spatial modelling, which has been used for modelling of air pollutant levels, and is available in the R-INLA package for the R statistics software. Covariates such as meteorological variables may be useful predictors in such models, but covariate misalignment must be dealt with. This paper describes a flexible method used to estimate pollutant levels for six pollutants in Suzhou, a city in China with dispersed air pollutant monitors and weather stations. A two-stage approach is used to address misalignment of weather covariate data.

Assessment of the Dynamic Exposure to PM2.5 Based on Hourly Cell Phone Location and Land Use Regression Model in Beijing

The spatiotemporal locations of large populations are difficult to clearly characterize using traditional exposure assessment, mainly due to their complicated daily intraurban activities. This study aimed to extract hourly locations for the total population of Beijing based on cell phone data and assess their dynamic exposure to ambient PM_2.5. The locations of residents were located by the cellular base stations that were keeping in contact with their cell phones. The diurnal activity pattern of the total population was investigated through the dynamic spatial distribution of all of the cell phones. The outdoor PM_2.5 concentration was predicted in detail using a land use regression (LUR) model. The hourly PM_2.5 map was overlapped with the hourly distribution of people for dynamic PM_2.5 exposure estimation. For the mobile-derived total population, the mean level of PM_2.5 exposure was 89.5 μg/m³ during the period from 2013 to 2015, which was higher than that reported for the census population (87.9 μg/m³). The hourly activity pattern showed that more than 10% of the total population commuted into the center of Beijing (e.g., the 5th ring road) during the daytime. On average, the PM_2.5 concentration at workplaces was generally higher than in residential areas. The dynamic PM_2.5 exposure pattern also varied with seasons. This study exhibited the strengths of mobile location in deriving the daily spatiotemporal activity patterns of the population in a megacity. This technology would refine future exposure assessment, including either small group cohort studies or city-level large population assessments.

Commuter PM exposure and estimated life-expectancy loss across multiple transportation modes in Xi'an, China

Commuters are reportedly exposed to severe traffic-related air pollution (TRAP) during their commuting trips. This study was designed and implemented to (1) compare particulate matter (PM) exposure across four common transportation modes; (2) examine and analyze various determining factors; and (3) estimate public health effects caused by commuting exposure to PM. All analyses and calculations were based on the experimental data collected from 13 volunteers, including heart-rate data on 336 commuting trips in four travel modes in Xi'an China. The results indicate highest PM exposure associated with cycling (average PM₁₀, PM_2.5 and PM_1.0 of 114.35, 72.37 and 56.51 μg/m³, respectively), followed by riding transit buses (116.29, 67.60 and 51.12 μg/m³ for the same pollutants, respectively), then taking a taxi (97.61, 58.87 and 45.11 μg/m³), and the lowest exposure onboard subways (55.86, 46.20 and 40.20 μg/m³). A multivariable linear regression model was used to examine major influences on PM concentration variations, with results corroborating significant PM variance across commuting modes, which is also affected by background pollution concentration and relative humidity. Further, years of life expectancy (YLE) loss were estimated using an inhalation dose model together with the life table method: cycling commuters experienced the greatest YLE loss (5.51-6.43 months per capita for the studied age group). During severe pollution periods, substituting other modes (like subway) for cycling could effectively avoid acute exposure. PM_2.5 levels in taxi cabins powered by CNG or methanol were comparatively lower, indicating that implementing alternative energy strategies could effectively lower traffic emissions and population exposure.

Systematic review and meta-analysis of recent high-quality studies on exposure to particulate matter and risk of lung cancer

BACKGROUND

Several aspects of the association between exposure to air pollution and risk of lung cancer remain unclear.

OBJECTIVE

We aimed at performing a meta-analysis of high-quality cohort studies on exposure to particulate matter (PM) 10 and PM2.5 and risk of lung cancer.

METHODS

We identified cohort studies published since 2004, that reported risk estimates of lung cancer for exposure to PM2.5 and PM10 adjusted for tobacco smoking and socioeconomic status, and conducted a meta-analysis based on random-effects models, including stratification by outcome, sex, country, tobacco smoking, and age.

RESULTS

Results on PM2.5 exposure were available from 15 studies; the summary relative risk (RR) for an increase of 10 μg/m³ was 1.16 (95% confidence interval [CI] 1.09, 1.23). The corresponding RR for PM10 exposure was 1.23 (95 CI 1.05, 1.40; seven studies). A higher risk was suggested in studies based on lung cancer mortality and in studies conducted in East Asia, while no difference was shown according to sex, smoking status or age. There was no suggestion of publication bias.

CONCLUSIONS

Our meta-analysis supported the hypothesis of an association between exposure to PM2.5 or PM10 and risk of lung cancer, and provided evidence that the magnitude of the risk might be higher than previously estimated, and might be modified by outcome and geographic region.

Particulate Matter Short-Term Exposition, Mobility Trips and COVID-19 Diffusion: A Correlation Analyses for the Italian Case Study at Urban Scale

The conjecture discussed in this paper was that the daily number of certified cases of COVID-19 is direct correlated to the average particular matter (PM) concentrations observed several days before when the contagions occurred (short-term effect), and this correlation is higher for areas with a higher average seasonal PM concentration, as a measure of prolonged exposure to a polluted environment (long-term effect). Furthermore, the correlations between the daily COVID-19 new cases and the mobility trips and those between the daily PM concentrations and mobility trips were also investigated. Correlation analyses were performed for the application case study consisting in 13 of the main Italian cities, through the national air quality and mobility monitoring systems. Data analyses showed that the mobility restrictions performed during the lockdown produced a significant improvement in air quality with an average PM concentrations reduction of about 15%, with maximum variations ranging between 25% and 42%. Estimation results showed a positive correlation (stronger for the more highly polluted cities) between the daily COVID-19 cases and both the daily PM concentrations and mobility trips measured about three weeks before, when probably the contagion occurred. The obtained results are original, and if confirmed in other studies, it would lay the groundwork for the definition of the main context variables which influenced the COVID-19 spread. The findings highlighted in this research also supported by the evidence in the literature and allow concluding that PM concentrations and mobility habits could be considered as potential early indicators of COVID-19 circulation in outdoor environments. However, the obtained results pose significant ethical questions about the proper urban and transportation planning; the most polluted cities have not only worst welfare for their citizens but, as highlighted in this research, could lead to a likely greater spread of current and future respiratory and/or pulmonary health emergencies. The lesson to be learned by this global pandemic will help planners to better preserve the air quality of our cities in the post-COVID-19 era.

Acute cardiorespiratory response to ambient air pollution exposure during short-term physical exercise in young males

BACKGROUND

Physical exercise in the presence of ambient air pollution may increase the absorbed dose of air pollutants. The combined effect of such exposure on cardiorespiratory function in young adults remains unclear.

AIM

To determine the acute cardiorespiratory responses in healthy young adults preforming submaximal physical exercise under exposure to high level winter-type ambient air pollution.

METHODS

Healthy young males (n=30) performed two separate 15-minute submaximal exercise trials on a cycle ergometer - when air pollutants' concentrations were increased (exposure trial) and when air quality was good (control trial). Each time blood pressure, pulse oximetry, spirometry and fractional exhaled nitric oxide (FeNO) were measured at baseline, directly after exercise and after 15-min of rest.

RESULTS

High air pollutants concentrations were observed during exposure trials (PM_2.5 24.0-157.0 μg/m³, SO₂ 8.7-85.8 μg/m³). Group-based correlation analysis showed statistically significant negative correlations between post-exercise declines in FEV₁/FVC and SO₂, PM₁₀ and PM_2.5 concentrations. In individual cases the decrease was recorded only in subjects who exercised under particularly high exposure, and was not related to their BMI, physical activity pattern or allergy status. In multivariate analysis SO₂ was a statistically significant predictor of both immediate (OR: 1.09, 95%CI: 1.01-1.17) and delayed decrease in airflow (OR: 1.08, 95%CI: 1.01-1.16), and PM_2.5 was also a statistically significantly explanatory variable of post-exercise decline in FEV₁/FVC (OR: 1.03, 95%CI: 1.00-1.06).

CONCLUSION

In young and healthy males exposure to ambient air pollution during short-term submaximal exercise is associated with a decrease in airflow (FEV₁/FVC) and the decrease is more apparent when the exercise takes place under particularly high exposure conditions.

Concentration-response relationships between hourly particulate matter and ischemic events: A case-crossover analysis of effect modification by season and air-mass origin

Most studies linking cardiovascular disease with particulate matter (PM) exposures have focused on total mass concentrations, regardless of their origin. However, the origin of an air mass is inherently linked to particle composition and possible toxicity. We examine how the concentration-response relation between hourly PM exposure and ischemic events is modified by air-mass origin and season. Using telemedicine data, we conducted a case-crossover study of 1855 confirmed ischemic cardiac events in Israel (2005-2013). Based on measurements at three fixed-sites in Tel Aviv and Haifa, ambient PM with diameter < 2.5 μm (PM_2.5) and 2.5-10 μm (PM_10-2.5) concentrations during the hours before event onset were compared with matched control periods using conditional logistic regression that allowed for non-linearity. We also examined effect modification of these associations based on the geographical origin of each air mass by season. Independent of the geographical origin of the air mass, we observed concentration-response curves that were supralinear. For example, the overall odds ratios (ORs) of ischemic events for an increase of 10-μg/m³ in the 2-h average of PM_10-2.5 were 1.08 (95% confidence interval (CI): 1.03-1.14) and 1.00 (0.99-1.01) at the median (17.8 μg/m³) and 95th percentile (82.3 μg/m³) values, respectively. Associations were strongest at low levels of PM_10-2.5 when air comes from central Europe in the summer (OR: 1.27; 95% CI: 1.06, 1.52). Our study demonstrates that hourly associations between PM_2.5 and PM_10-2.5 and ischemic cardiac events are supralinear during diverse pollution conditions in a single population that experiences a wide range of exposure levels.