Pollution Mitigation Measures Research Articles

Distinguishing the contributions of different smelting emissions to the spatial risk footprints of toxic elements in soil using PMF, Bayesian isotope mixing models, and distance-based regression

Toxic element pollution of soils emanating from smelting operations is an escalating global concern due to its severe impact on ecosystems and human health. In this study, soil samples were collected and analyzed to quantify the risk contributions and delineate the spatial risk footprints from smelting emissions for 8 toxic elements. A comprehensive health risk contribution and delineation framework was utilized, consisting of Positive matrix factorization (PMF), spatial interpolation, an advanced Bayesian isotope mixing model via Mixing Stable Isotope Analysis in R (MixSIAR), and distance-based regression. The results showed that the mean concentrations of As, Cd, Cu, Hg, Pb, and Zn exceeded the background levels, indicating substantial contamination. Three sources were identified using the PMF model and confirmed by spatial interpolation and MixSIAR, with contributions ranked as follows: industrial wastewater discharge and slag runoff from the smelter site (48.9 %) > natural geogenic inputs from soil parent materials (26.7 %) > atmospheric deposition of dust particles from smelting operations (24.5 %). Among the identified sources, smelter runoff posed the most significant risk, accounting for 97.9 % of the non-carcinogenic risk (NCR) and 59.9 % of the carcinogenic risk (CR). Runoff also drove NCR and CR exceedances at 7.8 % and 4.7 % of sites near the smelter, respectively. However, atmospheric deposition from smelting emissions affected soils across a larger 0.8 km radius. Although it posed lower risks, contributing just 1.1 % to NCR and 22.6 % to CR due to the limited elevation of toxic elements, deposition reached more distant soils. Spatial interpolation and distance-based regression delineated high NCR and CR exposure hotspots within 1.4 km for runoff and 0.8 km for deposition, with exponentially diminishing risks at further distances. These findings highlight the need for pathway-specific interventions that prioritize localized wastewater containment and drainage controls near the smelter while implementing broader regional air pollution mitigation measures.

Microplastics in seafood: Consumer preferences and valuation for mitigation technologies

Microplastics, an emerging pollutant, have garnered widespread attention due to potential repercussions on human health and the environment. Given the critical role of seafood in food security, growing concerns about microplastics might be detrimental to meeting future global food demand. This study employed a discrete choice experiment to investigate Chilean consumers’ preferences for technology aimed at mitigating microplastic levels in mussels. Using a between-subjects design with information treatments, we examined the impact of informing consumers about potential human health and environmental effects linked to microplastics pollution on their valuation for the technology. We found that the information treatments increased consumers’ willingness to pay for mussels. Specifically, consumers were willing to pay a premium of around US$ 4 for 250 g of mussel meat with a 90 % depuration efficiency certification. The provision of health impact information increased the price premium by 56 %, while the provision of environmental information increased it by 21 %. Furthermore, combined health and environmental information significantly increased the probability of non-purchasing behavior by 22.8 % and the risk perception of microplastics for human health by 5.8 %. These results emphasized the critical role of information in shaping consumer preferences and provided evidence for validating investment in research and development related to microplastic pollution mitigation measures.

Impact of single and combined local air pollution mitigation measures in an urban environment

Urban air pollution is one of the most important environmental problems for human health and several strategies have been developed for its mitigation. The objective of this study is to assess the impact of single and combined mitigation measures on concentrations of air pollutants emitted by traffic at pedestrian level in the same urban environment. The effectiveness of different scenarios of green infrastructure (GI), the implementation of photocatalytic materials and traffic low emission zones (LEZ) are investigated, as well as several combinations of LEZ and GI. A wide set of scenarios is simulated through Computational Fluid Dynamics (CFD) modelling for two different wind directions (perpendicular (0°) and 45° wind directions). Wind flow for the BASE scenario without any measure implemented was previously evaluated using wind-tunnel measurements. Air pollutant concentrations for this scenario are compared with the results obtained from the different mitigation scenarios. Reduction of traffic emissions through LEZ is found to be the most effective single measure to improve local air quality. However, GI enhances the effects of LEZ, which makes the combination of LEZ + GI a very effective measure. The effectiveness of this combination depends on the GI layout, the intensity of emission reduction in the LEZ and the traffic diversion in streets surrounding the LEZ. These findings, in line with previous literature, suggest that the implementation of GI may increase air pollutant concentrations at pedestrian level for some cases. However, this study highlights that this negative effect on air quality can turn into positive when used in combination with reductions of local traffic emissions.

AIR QUALITY AND PUBLIC HEALTH: A REVIEW OF URBAN POLLUTION SOURCES AND MITIGATION MEASURES

Urbanization has led to unprecedented challenges in maintaining air quality, significantly impacting public health. This review delves into the diverse sources of urban pollution and explores effective mitigation measures to safeguard public well-being. The rising concentration of pollutants in urban areas, primarily attributed to industrial activities, vehicular emissions, and domestic energy consumption, poses a severe threat to the respiratory and cardiovascular health of urban populations. The review begins by examining the key sources of urban pollution, highlighting the complex interplay between anthropogenic activities and their cumulative impact on air quality. Industrial emissions, characterized by the release of particulate matter, volatile organic compounds, and hazardous chemicals, contribute significantly to urban air pollution. Likewise, the surge in vehicular traffic, fueled by rapid urbanization, introduces pollutants such as nitrogen oxides and carbon monoxide, further exacerbating the problem. To address these challenges, the review explores a spectrum of mitigation measures. Implementation of stringent emission standards for industries, adoption of cleaner technologies, and promotion of renewable energy sources emerge as critical strategies. Additionally, urban planning initiatives focusing on efficient public transportation systems, pedestrian-friendly infrastructure, and green spaces are examined as effective means to reduce vehicular emissions and enhance air quality. The review also underscores the importance of public awareness campaigns and community engagement in fostering a collective commitment to air quality improvement. Innovative technological solutions, such as air quality monitoring networks and real-time data analytics, are discussed as indispensable tools for informed decision-making and prompt intervention. This review synthesizes current knowledge on urban pollution sources and mitigation measures, emphasizing the urgent need for a multidimensional approach to protect public health. By comprehensively addressing the intricate web of pollution contributors and implementing proactive measures, urban environments can be transformed into healthier and sustainable spaces for all residents.
 Keywords: Air Quality, Public Health, Urban Pollution, Mitigation, Review.

Contribution of Road Vehicle Tyre Wear to Microplastics and Ambient Air Pollution

Tyre particles are generated by shear forces between the tread and the road or by volatilisation. Tyre abrasion (wear) contributes from one-third to half of microplastics unintentionally released into the environment. The major part ends up in the soil, a considerable amount is released into the aquatic environment, and a small percentage becomes airborne. Nevertheless, tyre abrasion contributes to 5–30% of road transport particulate matter (PM) emissions. This corresponds to approximately 5% of total ambient PM emissions. The particle mass size distribution peak at around 20 to 100 μm, with a second peak in the 2–10 μm range. A nucleation mode has been reported in some studies. The absolute abrasion levels depend on the tyre, vehicle, and road characteristics, but also on environmental conditions and driving style. Most tyre particle emission factors in the literature are based on data prior to the year 2000. We aggregated recent studies and found a mean abrasion of 110 mg/km per vehicle or 68 mg/km/t for passenger cars (based on approximately 300 measurements). Based on a limited number of studies, the PM10 emissions were 1.4–2.2 mg/km per tyre. On the other hand, the particle number emissions were in the order of 1010 #/km per tyre. The ratio of PM10 to total abrasion was found to be 2.5% on average. Finally, the ratio of PM2.5 to PM10 was calculated to be around 40%. Various mitigation measures for tyre particle pollution could be envisaged; the most direct is the limitation of the tyre abrasion rate, as proposed by the European Commission for the Euro 7 regulation. Other regulatory initiatives are also discussed.

Application of Biological Methods and Remote Sensing in Marine Monitoring

Due to the serious side effects caused by poured nuclear sewage, marine monitoring ought to be paid much more attention than before. This article concludes two major general approaches, respectively biological methods and remote sensing. Biological methods contain specifically 4 different methods: ecological monitoring, biological monitoring, measurement of biological physiological and biochemical indicators, and determination of residual amounts of pollutants in the organism. Sensor monitoring technology based on marine organisms is a common technology, which desires marine life suitable for being sensor-equipped and well-developed tags to undergo successive monitoring. Biological detection methods are established by scientists in relevant fields to make up for the shortcomings of physical and chemical pollution detection. The remote sensing method, which includes a range of techniques such as satellite imagery, aerial photography, and sonar systems, offers a unique vantage point that allows us to observe and analyze large expanses of oceanic territory with unprecedented precision and efficiency. It can also be used to identify the sources of marine pollution, assess the impacts of marine pollution on marine ecosystems, monitor the effectiveness of pollution mitigation measures, and develop and implement policies to prevent marine pollution.

An energetics tale of the 2022 mega-heatwave over central-eastern China

It remains a major challenge to attribute heatwave’s lifecycle characteristics quantitatively to interwoven atmospheric and surface actions. By constructing a process-resolving, energetics-based attribution framework, here we quantitatively delineate the lifecycle of the record-breaking 2022 mega-heatwave over central-eastern China from a local energetics perspective. It is found that the cloudlessness induced radiative heating and atmospheric dynamics dominate the total energy buildup during the developing stage, while the land-atmosphere coupling and atmospheric horizontal advection act most effectively to sustain and terminate the heatwave, respectively. A reduction in anthropogenic aerosols provides a persistent positive contribution during the event, suggesting that pollution mitigation measures may actually increase the amplitudes of future heatwaves. With this framework, initial efforts are made to unravel culprits in a model’s sub-seasonal prediction of this mega-heatwave, demonstrating the framework’s potential for efficiently detecting the origins of climate extremes and quantitatively assessing the impacts of mitigation policies for sustainable development.

ADVANCE POLLUTION MONITORING SYSTEM WITH HEALTH CRITICAL GAS INDEXING USING IOT

The rise of urbanization and industrialization has led to an increase in pollution, posing serious risks to human health and the environment. Consequently, the development of advanced pollution monitoring systems has become crucial for efficient pollution control and management. This abstract introduces a cutting-edge pollution monitoring system based on the Internet of Things (IoT), which incorporates health critical gas indexing to provide real-time and precise information about air quality. The proposed system utilizes IoT technology to create a network of interconnected sensors installed in various locations within cities or industrial areas. These sensors are designed to measure the concentration of pollutants such as carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), particulate matter (PM2.5 and PM10), and ozone (O3) in the surrounding air. The collected data is wirelessly transmitted to a central monitoring station for analysis and visualization. To assess the health risks associated with measured pollutant levels, a health critical gas indexing algorithm is employed. This algorithm considers pollutant concentrations and their corresponding health effects based on established air quality guidelines and standards, calculating an index value that indicates the overall health impact on the exposed population. The monitoring system provides real-time updates and alerts to relevant stakeholders, including government authorities, environmental agencies, and the public. Accessible through a userfriendly web or mobile application, the data and index values empower users to make informed decisions regarding outdoor activities, pollution mitigation measures, and health precautions. Compared to traditional monitoring approaches, the IoT-based advance pollution monitoring system with health critical gas indexing offers several advantages. It provides a comprehensive and accurate assessment of air quality by considering the specific health risks posed by different pollutants. Its real-time nature enables prompt actions and interventions to mitigate pollution levels, safeguarding public health and the environment. Furthermore, the availability of data empowers policymakers and researchers to analyze trends, identify pollution sources, and develop targeted pollution control strategies. In conclusion, the proposed IoT-based advance pollution monitoring system with health critical gas indexing represents a significant advancement in pollution monitoring and management. By leveraging IoT technology and incorporating health-related considerations, the system enables effective and proactive pollution control measures, leading to improved air quality and overall well-being of the population.

Global PM2.5 Prediction and Associated Mortality to 2100 under Different Climate Change Scenarios.

Ambient fine particulate matter (PM2.5) has severe adverse health impacts, making it crucial to reduce PM2.5 exposure for public health. Meteorological and emissions factors, which considerably affect the PM2.5 concentrations in the atmosphere, vary substantially under different climate change scenarios. In this work, global PM2.5 concentrations from 2021 to 2100 were generated by combining the deep learning technique, reanalysis data, emission data, and bias-corrected CMIP6 future climate scenario data. Based on the estimated PM2.5 concentrations, the future premature mortality burden was assessed using the Global Exposure Mortality Model. Our results reveal that SSP3-7.0 scenario is associated with the highest PM2.5 exposure, with a global concentration of 34.5 μg/m3 in 2100, while SSP1-2.6 scenario has the lowest exposure, with an estimated of 15.7 μg/m3 in 2100. PM2.5-related deaths for individuals under 75 years will decrease by 16.3 and 10.5% under SSP1-2.6 and SSP5-8.5, respectively, from 2030s to 2090s. However, premature mortality for elderly individuals (>75 years) will increase, causing the contrary trends of improved air quality and increased total PM2.5-related deaths in the four SSPs. Our results emphasize the need for stronger air pollution mitigation measures to offset the future burden posed by population age.

Occupational respiratory morbidity and associated factors among hairdressers in Ethiopia: a cross-sectional study

ObjectiveThis study was designed to determine the prevalence and factors associated with occupational respiratory morbidity among hairdressers in Northwestern Ethiopia.DesignA cross-sectional study was conducted from 6 July 2022 to 17...

School Children’s exposure to 〖PM〗_(2.5) in a high pollution area of Bogotá, Colombia

Approximately 93% of the world’s children under 15 are exposed to ambient PM2,5 levels exceeding the World Health Organization’s guidelines. PM2,5 and other air pollutants affect children’s mental and motor development, as well as their lung function, even at low concentrations. In low- and middle-income countries, the effects are potentially stronger because of the weaker land-use policies in place, which increases households’ proximity to industrial sources. Such is the case of areas with mixed land use in western Bogota, Colombia. In this work, the exposure of children to PM2,5 at a school in the Puente Aranda district was estimated. PM2,5 concentrations were measured using low-volume area samplers during school hours in February 2020. Information on the children’s daily activity was recorded in order to estimate the physical effort applied during their normal school activities, and the minors’ respiratory symptomatologies were consulted with their parents. The inhaled dose was estimated using inhalation rates. The results showed that children aged three to five inhale the highest doses and report higher rates of respiratory symptoms. Indoor PM2,5 concentrations were consistently higher, agreeing with previous reports, probably because of dust resuspension and poor classroom ventilation. Air pollution mitigation measures must be put into effect in order to protect this highly vulnerable population. These measures will also positively affect the safe return of students to school activities after the pandemic lockdown.

ASSESSMENT OF NOISE LEVELS AND HEALTH-RELATED PROBLEMS IN SELECTED HOSPITALS IN ABEOKUTA, NIGERIA

Exposure to high noise levels in the hospital reportedly has negative effects on patients' health and reduces the productivity of the workers. This study assessed the noise levels in the various activity areas in some hospitals and their associated health effects in Abeokuta. The noise levels were measured using a digital sound level meter (Smart sensor DSLM). A descriptive cross-sectional survey was also conducted to examine the perception, effects, awareness and mitigation measures of noise among the hospital staff and patients. The observed mean noise levels in decibels (dB) throughout the activity areas in the hospitals ranged from 61.1-76.9dB (FMC), 62.0-74.3dB (SH), 63.4-71.4dB (SHH), 66.0-81.5dB (HC), and 59.0-66.7dB (KPH). The noise level was higher in the outpatient department and exceeded the WHO-recommended average noise levels in hospitals. Annoyance, distraction and stress were the most commonly reported noise effects among staff and patients in all hospitals. There was low awareness of noise effects and poor knowledge of mitigation measures for noise pollution among the respondents. Implementation of training to promote awareness of noise, enforcement and compliance with existing policies on noise prevention and control in healthcare facilities are highly recommended.

Economic analysis of exposure to the elevated level of PM10 in Vietnam: a COI and WTP approach

To understand the harm caused by air pollution and attract attention from government agencies, this study estimates the exposure to the elevated level of PM10 and its effect on health. This study employed two distinct approaches: cost-of-illness (COI) and willingness-to-pay (WTP). The results revealed that people are willing to pay for risk reduction initiatives, and the difference between COI and WTP is negligible. The entire sum estimated from the COI and WTP is adequate to pay the complete expenses of air pollution mitigation measures such as the deployment of Bus Rapid Transit. Therefore, government officials may concentrate on the best technique for lowering air pollution, notably in Vietnam. In the short term, hiking taxes to reduce carbon emissions in the city and implementing a subsidy plan for impacted stakeholders may be necessary. On the other hand, long-term solutions may include economic transformation and the building of a greener metropolis.

Long-Term Exposure to Fine Particulate Matter and Incidence of Esophageal Cancer: A Prospective Study of 0.5 Million Chinese Adults

Evidence is sparse and inconclusive on the association between long-term fine (≤2.5 μm) particulate matter (PM2.5) exposure and esophageal cancer. We aimed to assess the association of PM2.5 with esophageal cancer risk and compared the esophageal cancer risk attributable to PM2.5 exposure and other established risk factors. This study included 510,125 participants without esophageal cancer at baseline from China Kadoorie Biobank. A high-resolution (1× 1 km) satellite-based model was used to estimate PM2.5 exposure during the study period. Hazard ratios (HR) and 95% CIs of PM2.5 with esophageal cancer incidence were estimated using Cox proportional hazard model. Population attributable fractions for PM2.5 and other established risk factors were estimated. There was a linear concentration-response relationship between long-term PM2.5 exposure and esophageal cancer. For each 10-μg/m3 increase in PM2.5, the HR was 1.16 (95% CI, 1.04-1.30) for esophageal cancer incidence. Compared with the first quarter of PM2.5 exposure, participants in the highest quarter had a 1.32-fold higher risk for esophageal cancer, with an HR of 1.32 (95% CI, 1.01-1.72). The population attributable risk because of annual average PM2.5 concentration ≥35 μg/m3 was 23.3% (95% CI, 6.6%-40.0%), higher than the risks attributable to lifestyle risk factors. This large prospective cohort study of Chinese adults found that long-term exposure to PM2.5 was associated with an elevated risk of esophageal cancer. With stringent air pollution mitigation measures in China, a large reduction in the esophageal cancer disease burden can be expected.

Four decades of aviation visibility at Bhairahawa airport, gateway to Buddha's birthplace Lumbini, Nepal

Over four decades of visibility data at Bhairahawa airport (BWA), a recently upgraded international airport near Lumbini, a UNESCO heritage site in Nepal has been analyzed. In this study, we also investigated one of the important microclimatic behavior of fog i.e., onset and dispersal timings, and its implication on aviation. Temporal variations of poor visibility conditions at BWA are found to be primarily associated with variations in haze and fog. Haze at BWA accounts for the highest percentage (∼27%) of time and its annual occurrence is increasing (0.57% yr−1). There is a significant upward trend of hazy days in all seasons, the highest (1.46% day yr−1) being in post-monsoon. The overall seasonal poor visibility, too, has increased significantly in all seasons, with the highest trend in post-monsoon (1.57% yr−1). Similarly, fog frequency in the winter season has also increased noticeably for fog days (1.05% day yr−1), dense fog days (0.51% day yr−1), general fog hours (0.55% hour yr−1) and dense fog hours (0.20% hour yr−1). We found that fog at BWA is usually formed overnight and dissipates before noon. Daytime onset and late dispersion of fog are more common in the peak winter months of December and January. Further, we investigated the relationship between visibility and aerosol optical depth (AOD) and found a moderate negative correlation (r = − 0.66, p < 0.001) between them in the monsoon season. However, AOD is found to have a weaker correlation with visibility during winter (r = −0.36) and pre-monsoon (r = −0.23) seasons, when there is a more pronounced influence of meteorological conditions on the occurrence of visibility. We have observed a better correlation (r = −0.74) between fine particulate matter concentration (PM2.5) and visibility. Examining the effect of relative humidity (RH) on AOD (or, PM2.5) and visibility revealed that higher RH tends to lower visibility. Visibility at BWA airport is gradually worsening due to local and regional air pollution emissions and changing meteorological conditions. The degraded visibility at BWA airport will negatively impact flight safety and timeliness. Effective implementation of regionally coordinated air pollution mitigation measures can be a sustainable step towards the improvement of visibility in long run. However, the installation of ground equipment like CAT-II/III Instrument Landing System (ILS) for aircraft take-off and landings, and advanced surface movement guidance and control system (A-SMGCS) are highly advisable to lessen the damage potential to aviation.

COPD deaths attributable to ozone in 2019 and future projections using the WHO AQG 2021 in urban China

Chronic obstructive pulmonary disease (COPD) is an epidemic in China. Ozone is a possible risk factor of COPD, with ozone concentrations increasing in China, despite air pollution mitigation measures that reduced particulate matter. The WHO Air Quality Guidelines (AQG) recommendations in 2021 are a turning point that formally recognizes the crucial role of indoor air pollution. We aimed to investigate the premature COPD deaths attributable to ozone in 2019, taking the WHO AQG 2021 level into account to determine the gap to bridge ozone control in China. First, we assessed ozone exposures initiated from indoor and outdoor sources by gender and age groups in 344 cities under four scenarios: 2019 as a baseline, and outdoor ozone at WHO AQG 2021 level in 2019, 2030, and 2050, respectively. Subsequently, we estimated COPD deaths attributable to ozone. The results show that the COPD deaths attributable to ozone are 77,737 in 2019, and 527, 872, 1355 if the outdoor ozone concentration is reduced to the WHO AQG 2021 level in 2019 (counterfactual scenario), 2030, and 2050, respectively in urban China. The indoor ozone sources only contribute to less than 5% of COPD deaths. A gap of 68.5 μg/m3 for the highest seasonal ozone concentration should be bridged to meet the WHO AQG 2021 and avoid over 76 thousand (98%) COPD deaths in 2019 in urban China.

Acoustic disturbance in blue mussels: sound-induced valve closure varies with pulse train speed but does not affect phytoplankton clearance rate

Abstract Anthropogenic sound has increasingly become part of the marine soundscape and may negatively affect animals across all taxa. Invertebrates, including bivalves, received limited attention even though they make up a significant part of the marine biomass and are very important for higher trophic levels. Behavioural studies are critical to evaluate individual and potentially population-level impacts of noise and can be used to compare the effects of different sounds. In the current study, we examined the effect of impulsive sounds with different pulse rates on the valve gape behaviour and phytoplankton clearance rate of blue mussels (Mytilus spp.). We monitored the mussels’ valve gape using an electromagnetic valve gape monitor and their clearance rate using spectrophotometry of phytoplankton densities in the water. We found that the mussels’ valve gape was positively correlated with their clearance rate, but the sound exposure did not significantly affect the clearance rate or reduce the valve gape of the mussels. They did close their valves upon the onset of a pulse train, but the majority of the individuals recovered to pre-exposure valve gape levels during the exposure. Individuals that were exposed to faster pulse trains returned to their baseline valve gape faster. Our results show that different sound exposures can affect animals differently, which should be taken into account for noise pollution impact assessments and mitigation measures.

Escaping from Air Pollution: Exploring the Psychological Mechanism behind the Emergence of Internal Migration Intention among Urban Residents.

Rapid urbanization with poor city planning has resulted in severe air pollution in urban areas of low- and middle-income countries. Given the adverse impacts of air pollution, citizens may develop ideation of averting behaviors, including migration to another region. The current study explores the psychological mechanism and demographic predictors of internal migration intention among urban people in Hanoi, Vietnam—one of the most polluted capital cities in the world. The Bayesian Mindsponge Framework (BMF) analytics was used to construct a model and perform Bayesian analysis on a stratified random sampling dataset of 475 urban people. We found that migration intention was negatively associated with an individual’s satisfaction with air quality. The association was moderated by the perceived availability of a nearby alternative (i.e., a nearby province/city with better air quality). The high migration cost due to geographical distance made the moderation effect of the perceived availability of a faraway alternative negligible. These results validate the proposed psychological mechanism behind the emergence of migration intention. Moreover, it was found that male and young people were more likely to migrate. While the brain drain effect did not clearly show, it is likely due to complex underlying interactions of various related factors (e.g., age and gender). The results hint that without air pollution mitigation measures, the dislocation of economic forces might occur and hinder sustainable urban development. Therefore, collaborative actions among levels of government, with the environmental semi-conducting principle at heart, are recommended to reduce air pollution.

Investigation of air pollution mitigation measures, ventilation, and indoor air quality at three schools in London

In UK urban areas, due to ease of accessibility and convenience, many schools are located close to main busy roads. This often results in pollution hotspots around schools due to on-road vehicular pollutant emissions, especially during drop-off and pick-up times of students to and from schools. As well as being exposed to air pollutants in the school grounds, students are also exposed indoors. Thus, the need for scientific investigations focusing on mitigation of air pollution exposure indoors and outdoors for schools has significantly increased. The main objectives of the present study were therefore to: 1) obtain a clearer understanding of the extent of the air pollution problem inside and around schools and the factors that affect it; and 2) determine how it may be mitigated effectively using a range of interventions. These were achieved by carrying out monitoring of air pollution and associated parameters in and around three primary schools in London, UK. The study investigated the exposure reduction potential of various interventions, such as green screens, air purifiers, and school streets. A good understanding was obtained of the improvement in air quality that was achieved by the interventions both inside and outside the classrooms in the three schools. A green screen along the fences of the school reduced PM concentration by up to 44% in the playground. Installing air purifiers in a classroom resulted in lowering in PM concentration of about 57%. The school street initiative decreased PM concentration by about 36% in front of the school during pick up time. From the overall findings, practical recommendations have been included, as far as has been possible, that will enable formal guidance to be produced to help improve air quality in and around UK schools.

Source-specific health risks induced by PM2.5-bound metallic species under different pollution scenarios in a cold megacity of Northeast China

As minor fractions of PM2.5, metallic species are particularly associated with health risks. Furthermore, the health risks and health risk-involved source contributions induced by them might be discrepant under different pollution scenarios. To this end, this study first sampled fine particulate matter (PM2.5) in the Harbin city, China from May 2017 to April 2018, then compared the concentrations of 22 PM2.5-bound metallic species in five pollution scenarios (heating season, non-heating season, clean days (C), slightly polluted days (SP), and heavily polluted days (HP)), and finally assessed the source-involved health risks. During the sampling period, the average concentration of metallic elements was 4.58 μg m−3, constituted a minor fraction (4.75%) in PM2.5. The CR values induced by PM2.5-bound metals were 6.72 × 10−4–8.07 × 10−4 for adults and 1.26 × 10−4–1.51 × 10−4 for children, while HQ values were 1.92–2.67 for adults and 0.36–0.50 for children. The comparative analysis indicates that most metallic elements recorded higher mass concentration and health risk values in the heating season than those in the non-heating season, and followed the ascending gradient of C–SP–HP. Using the positive matrix factorization model (PMF), coal combustion (12.14% ~ 43.50% for children and 11.96% ~ 43.21% for adults) and traffic emission (6.91% ~ 32.37% for children and 6.91% ~ 32.27% for adults) were the dominant sources of CR values; while coal combustion (6.49% ~ 53.40% for children and 12.03% ~ 38.23% for adults), traffic emission (5.55% ~ 34.91% for children and 11.78% ~ 31.34% for adults), and mineral dust (8.67% ~ 54.31% for children and 11.35% ~ 37.29% for adults) were the dominant sources of HQ values. Moreover, the health risks induced by sea salt were higher in non-heating season than those in heating season, while the health risks induced by traffic emission were on the contrary. The findings of this study may have significance in promoting metal-involved health risk alleviation and formulating health-oriented pollution mitigation measures.