Air Quality Thresholds Research Articles

Spatial Analysis of Sulfur Dioxide (SO2) and Nitrogen Dioxide (NO2) Distribution Using Getis-Ord Gi* in DKI Jakarta Region, Indonesia

Abstract The increasing mobility of population and industry is the main problem in this study, so it will affect the spatial pattern in the distribution of pollutants. The parameters to measure air quality are Sulfur Dioxide and Nitrogen Dioxide. This study aims to (1) analyze air quality distribution patterns with SO2 and NO2 concentration parameters in the DKI Jakarta area in 2021, (2) analyze ambient air quality distribution patterns based on air quality threshold values, and (3) analyze the spatial distribution of SO2 and NO2 in the DKI Jakarta area in 2021. The data used for this research is the average concentration data of SO2 and NO2 pollutants in DKI Jakarta in 2021. This research uses the interpolation method using Inverse Distance Weighting and Getis-Ord Gi*. The results of this research show that the concentration of pollutants that have been interpolated using Inverse Distance Weighting produces higher NO2 than SO2. From the interpolated image, a Hot Spot analysis (Getis-Ord Gi*) was conducted. This analysis showed significant clustering of nearest neighbors, with high concentrations of SO2 in East Jakarta and NO2 in West Jakarta. Therefore, air quality needs to be monitored and managed to maintain environmental stability.

Paris air quality monitoring for the 2024 Olympics and Paralympics: focus on air pollutants and pollen

BackgroundExposure to air pollution can affect the health of individuals with respiratory disease, but may also impede the health and performance of athletes. This is potentially relevant for people travelling...

Using a Low-Cost Sensor to Estimate Fine Particulate Matter: A Case Study in Samutprakarn, Thailand

This study evaluates low-cost sensors (LCSs) for measuring coarse and fine particulate matter (PM) to clarify and measure air pollution. LCSs monitored PM10, PM2.5 (fine particulates), and PM1.0 concentrations at four sites in Samutprakarn, Thailand from December 2021 to April 2022. Average daily PM10, PM2.5, and PM1.0 concentrations at the monitoring locations were 53–79, 34–45, and 31–43 μg/m3, respectively. In December 2021, the monitoring station had a daily PM2.5 value above 100 μg/m3, indicating haze occurrences. However, the monitoring site’s daily PM10 and PM1.0 concentrations did not surpass Thailand’s ambient air quality threshold. We also measured and calibrated comparative particulate matter concentrations from LCSs and a tapered element oscillating microbalance (TEOM) monitor (Pollution Control Department (PCD) standard analytical method). PM2.5 concentrations from the LCSs were lower than TEOM, but the difference was not statistically significant. The PM2.5 monitoring station provided near-real-time air quality data for health risk reduction, especially when PM levels were high. Based on this study, authorities and local agencies may consider improving air quality regulation in Samutprakan, focusing on suburban PM2.5 air pollution.

Revised EU and WHO air quality thresholds: Where does Europe stand?

One year after the new WHO Global Air Quality Guidelines were published, the European Commission proposed revisions to the Ambient Air Quality Directives, seeking to align European Union air quality standards more closely with WHO recommendations. Here, we employed Bayesian geostatistical regression models to estimate at 1km2 spatial resolution the number of Europeans that would be currently exposed to levels above the new suggested thresholds for the three most harmful pollutants, namely PM2.5, PM10, and NO2. The results have shown that in 2021, 97.6% (95% credible interval: 95.1, 99.2%) of the total European population was exposed to PM2.5 levels exceeding the new WHO annual limit values, while 47.5% (36.2, 59.5%) lived in areas where the revised EU thresholds were exceeded. For PM10, the proportion of people exposed to concentrations above the WHO annual thresholds was estimated at 62.5% (54.0, 70.9%) and at 29.6 (21.9, 37.0%) above the EU values, whereas for NO2, the estimates were at 67.4% (57.9, 75.8%) and 20.2% (13.3, 28.5%), respectively. Our high-resolution model-based predictions are readily available to support policy makers and scientists working toward achieving the ambitious European zero-pollution vision for 2050.

Selective turn-on fluorescence detection of formaldehyde in the gas phase

Reliable detection of formaldehyde in gas phase still remains a challenge regarding either sensitivity or selectivity or both. In this study we report on a simple, unique sensor composite, which enables efficient detection of gaseous formaldehyde with both low limit of detection (LOD) and extremely high selectivity. The primary components of the sensor composite include a hydroxylamine sulfuric acid salt ((NH2OH)2·H2SO4) and a fluorescence turn-on probe, which both are coated within the porous matrix of a cellulose plate. The fluorescence probe is based on a perylene diimide (PDI) molecule modified with an aniline group, which is non-fluorescent in its pristine state due to the photoinduced intramolecular electron transfer. Upon interaction with formaldehyde, the hydroxylamine salt will be converted to the corresponding Schiff base through aldimine condensation, releasing the sulfuric acid. The acid released will protonate the aniline group on PDI, resulting in a quick fluorescence turn-on. By measuring the fluorescence increase we can detect formaldehyde both quantitatively and specifically. Under the optimized condition, the sensor demonstrated a LOD of 3.7 ppb, which is much lower than the air quality threshold set by WHO. The sensor was also proven highly selective towards formaldehyde, with negligible response towards other common chemicals. The work reported will not only provide a new sensor for formaldehyde, but moreover open a unique design pathway for sensor composite that combines reactive components with various fluorescence indicators so as to enable highly efficient detection of many other air pollutants and toxic chemicals.

Driver mutations and air pollution in advanced non-small cell lung cancer (NSCLC) at two reference hospitals in Mexico City.

e20545 Background: Currently, precision medicine has allowed the classification of NSCLC according to the profile of driver mutations and the development of highly effective treatments. There is evidence to support the relationship between outdoor air pollution, particularly particulate matter (PM) in outdoor air, with lung cancer incidence and mortality. Smoking is a negative predictor of EGFR mutation, but the effect of air pollution has not been stablished. Methods: We perform a retrospective study in two referral hospitals in Mexico City between 2015 to 2020 to determinate the frequency of key driver mutations in patients with advanced NSCLC and the relation with smoking habit, wood smoke exposure and pollution indexes (PM2.5, PM10, SO2, O3, NO2) according to their place of residence. We used WHO air quality thresholds for air pollutants to classify cases with high or low exposure. Results: A total of 1277 cases were analyzed. The median age at diagnosis was 66 years (range 18-97 years), 53% were females and 49.6% had history of smoking habit. According to histology, 61.6% of cases corresponded to adenocarcinoma, 11.7% were squamous, 1.3% large cell, and 25.4% indeterminate. Wood smoke was assessed in 83.1% of cases and 28.5% had exposure history. Air pollutants were measured in half of cases, high level of exposure for PM2.5, PM10, NO2 and SO2 occurred in 63.2%, 30.8%, 15.6%, 53.4%, respectively. EGFR, ALK and KRAS mutations were evaluated in 85%, 16.7% and 8.6% of patients, respectively. The presence of these mutations was: EGFR 17.1%, ALK 11.1%, and KRAS 16.5%. Patients with EGFR-positive NSCLC were more frequently female (65.1% vs 34.9%, OR 1.8 95%CI 1.4-2.5, p < 0.001) and had no history of tobacco use (35% vs 65%, OR 0.49 95%CI 0.36-0.67, p < 0.001). Wood smoke was not statistically significant. High exposure to PM2.5 was most common in patients with non-mutated EGFR NSCLC (65.3% vs 34.7%, OR 1.7 95%CI 1.2-2.5, p = 0.006). Relationship with other air pollutants were not statistically significant. ALK-positive NSCLC patients tend to be females (68% vs 32%, p = 0.07) and had no history of smoking habit (20.8% vs 79.2% OR 0.28 95%CI 0.1-0.78, p = 0.01). High exposure to SO2 was common (78.6% vs 21.4% p = 0.05). Association in KRAS-positive NSCLS patients were not found. Conclusions: A low rate of key driver mutations assessment was found in this Mexican cohort. Clinical profile of NSCLC EGFR positive is according with previous reports in the literature. Exposure to PM2.5 and SO2 were found associated with EGFR and ALK status in this retrospective study and are hypothesis generating information.

Long-term airborne particle pollution assessment in the city of Coyhaique, Patagonia, Chile

An air pollution assessment in a small city located in the heart of Chilean Patagonia is presented. Seven years (2014–2020) of PM concentration levels retrieved from two monitoring stations permits an evaluation of the city's pollution variability, the effect of meteorological variables and long-term trends of air pollution. The highest PM concentration levels observed during the coldest months are mainly related to an increasing emission associated with the intensive use of firewood for residential heating and cooking. The most polluted days are associated with low temperatures, low wind speed and high PM2.5/PM10 ratios, which is consistent with the predominance of local firewood sources over background emissions. A decrease in both PM fractions over time has been estimated (PM10: -4.1, CI99%: −5.7 to −2.9 and PM2.5: -2.2, CI99%: −3.5 to −1.3 μg m−3 year−1). However, the annual average PM mass concentrations in Coyhaique exceeded both national and international air quality thresholds. The city reported a percent of annual exceedances of the daily WHO guidelines of 57% for PM10 and 77% for PM2.5. These numbers highlight the serious air pollution problem of the city of Coyhaique, which exhibits air pollution levels comparable to those of many polluted megacities in the world.

Evaluating of IAQ-Index and TVOC Parameter-Based Sensors for Hazardous Gases Detection and Alarming Systems.

The measurement of air quality parameters for indoor environments is of increasing importance to provide sufficient safety conditions for workers, especially in places including dangerous chemicals and materials such as laboratories, factories, and industrial locations. Indoor air quality index (IAQ-index) and total volatile organic Compounds (TVOC) are two important parameters to measure air impurities or air pollution. Both parameters are widely used in gases sensing applications. In this paper, the IAQ-index and TVOCs have been investigated to identify the best and most flexible solution for air quality threshold selection of hazardous/toxic gases detection and alarming systems. The TVOCs from the SGP30 gas sensor and the IAQ-index from the SGP40 gas sensor were tested with 12 different organic solvents. The two gas sensors are combined with an IoT-based microcontroller for data acquisition and data transfer to an IoT-cloud for further processing, storing, and monitoring purposes. Extensive tests of both sensors were carried out to determine the minimum detectable volume depending on the distance between the sensor node and the leakage source. The test scenarios included static tests in a classical chemical hood, as well as tests with a mobile robot in an automated sample preparation laboratory with different positions.

Effects of Ambient Exposure to Nitrogen Dioxide on Outpatient Visits for Psoriasis in Rapidly Urbanizing Areas

Rapid development and urbanization can increase ambient exposure to NO2 and its health risks in individuals. However, the association between NO2 exposure and outpatient visits of patients with psoriasis has rarely been reported, though psoriasis is a major skin disease in rapidly urbanizing areas with high population densities. This study applied a time-stratified case-crossover design to investigate the effect of short-term exposure to ambient NO2 on outpatient visits for psoriasis from 2014 to 2020 in Guangzhou, China (n = 62,305). A subgroup analysis was performed to evaluate NO2 impacts on vulnerable subpopulations. Our results showed that the NO2 concentration during the study period was lower than that of the level II threshold from China (PRC) but higher than that set by the WHO, indicating moderate air quality. However, a 10-µg m-3 increase in NO2 concentration could still be associated with 3.1% higher outpatient visits for psoriasis (adjusted RR of lag 0 d:1.031 [CI:1.025, 1.037]). NO2 exposure can also pose long-term risks. Additionally, NO2 impacts on psoriasis may be independent of other pollutants. Adjusting for PM2.5, SO2, O3, and meteorological factors, a 10-µg m-3 increase in NO2 was associated with RRs of 1.043 [CI:1.033, 1.053], 1.022 [CI:1.014, 1.031], and 1.022 [CI:1.014, 1.031] at lag 0, lag 1, and lag 2 days, respectively. NO2 risks were higher among older individuals (age ≥ 60 years) and those with medical insurance [adjusted RRs: 1.045 (CI:1.023, 1.066) and 1.047 (CI:1.036, 1.058)]. Being a major pollutant in rapidly urbanizing areas with high population densities, NO2 emission could be a crucial factor in psoriasis, although the daily pollution level was not above the air quality thresholds. Challenges associated with air quality control and health disparity create a necessity for the enhancement of health and environmental policies to reduce local and regional emissions (e.g., traffic-related pollution), and vulnerable subpopulations should be targeted.

Potential impacts of Washington State's wildfire worker protection rule on construction workers.

Driven by climate change, wildfires are increasing in frequency, duration, and intensity across the Western United States. Outdoor workers are being exposed to increasing wildfire-related particulate matter and smoke. Recognizing this emerging risk, Washington adopted an emergency rule and is presently engaged in creating a permanent rule to protect outdoor workers from wildfire smoke exposure. While there are growing bodies of literature on the exposure to and health effects of wildfire smoke in the general public and wildland firefighters, there is a gap in knowledge about wildfire smoke exposure among outdoor workers generally and construction workers specifically—a large category of outdoor workers in Washington totaling 200,000 people. Several data sources were linked in this study—including state-collected employment data and national ambient air quality data—to gain insight into the risk of PM2.5 exposure among construction workers and evaluate the impacts of different air quality thresholds that would have triggered a new Washington emergency wildfire smoke rule aimed at protecting workers from high PM2.5 exposure. Results indicate the number of poor air quality days has increased in August and September in recent years. Over the last decade, these months with the greatest potential for particulate matter exposure coincided with an annual peak in construction employment that was typically 9.4–42.7% larger across Washington counties (one county was 75.8%). Lastly, the ‘encouraged’ threshold of the Washington emergency rule (20.5 μg m−3) would have resulted in 5.5 times more days subject to the wildfire rule on average across all Washington counties compared to its ‘required’ threshold (55.5 μg m−3), and in 2020, the rule could have created demand for 1.35 million N-95 filtering facepiece respirators among construction workers. These results have important implications for both employers and policy makers as rules are developed. The potential policy implications of wildfire smoke exposure, exposure control strategies, and data gaps that would improve understanding of construction worker exposure to wildfire smoke are also discussed.

Paper-Based Vapor Detection of Formaldehyde: Colorimetric Sensing with High Sensitivity

We report on a novel colorimetric sensor system for highly sensitive detection of formaldehyde (FA) in the gas phase. The sensor is constructed with paper towel as a substrate coated with the sulfuric acid salt of hydroxylamine ((NH2OH)2·H2SO4) together with two pH indicators, bromophenol blue and thymol blue. Upon exposure to FA, the hydroxylamine will react with the absorbed FA to form a Schiff base (H2C=N-OH), thus releasing a stoichiometric amount of sulfuric acid, which in turn induces a color change of the pH indicator. Such a color change was significantly enriched by incorporating two pH indicators in the system. With the optimized molar ratio of the two pH indicators, the color change (from brown to yellow, and to red) could become so dramatic as to be visible to the eye depending on the concentration of FA. In particular, under 80 ppb of FA (the air quality threshold set by WHO) the color of the sensor substrate changes from brown to yellow, which can even be envisioned clearly by the naked eyes. By using a color reader, the observed color change can be measured quantitatively as a function of the vapor concentration of FA, which produces a linear relationship as fitted with the data points. This helps estimate the limit of detection (LOD), to be 10 ppb under an exposure time of 10 min, which is much lower than the air quality threshold set by WHO. The reported sensor also demonstrates high selectivity towards FA with no color change observed when exposed to other common chemicals, including solvents and volatile organic compounds. With its high sensitivity and selectivity, the proposed paper-based colorimetric sensor thus developed can potentially be employed as a low-cost and disposable detection kit that may find broad application in detecting FA in indoor air and many other environments.

Substantial Reduction in Particulate Matter Air Pollution across Europe during 2006-2019: A Spatiotemporal Modeling Analysis.

Air pollution poses the largest environmental health risk in Europe. Particulate matter (PM) concentrations are the most harmful pollutants representing the main air quality indicator in the Sustainable Development Goals (SDGs). The air quality surveillance in Europe is based on a monitoring network that is too coarse for a comprehensive evaluation of the air pollution burden. We link raw pollutant data with remotely sensed products using Bayesian geostatistical models and for the first time estimate pan-European near-surface concentrations of both fine (PM2.5) and coarse (PM10) particles at 1 km2 spatial resolution during 2006–2019. We evaluate the compliance with the air quality thresholds set by the World Health Organization (WHO) and the European Union (EU) and assess country-wise trends. The results show that during the last 14 years, PM10 and PM2.5 concentrations declined by 36.5% (95% credible interval: 30.3, 41.9%) and 39.1% (26.6, 50.5%), respectively. The number of people exposed to PM10 levels above the WHO thresholds decreased from 78.3% (52.6, 91.8%) in 2006 to 28.4% (16.2, 43.7%) in 2019; for PM2.5, the decrease was smaller: from 91.0% (61.3, 99.1%) exposed in 2006 to 53.6% (33.5, 76.3%) in 2019. Although there is a clear improvement in the overall picture, stricter measures are needed to ensure compliance with the WHO guidelines.

Estimating the Potential Health Benefits of Air Quality Warnings.

National, state, and local air quality authorities issue warnings urging residents to stay indoors or to take other precautions when pollutant levels are expected to exceed defined thresholds. Previous work explores the impact of warnings on specific activities but not the health improvements that might result if individuals fully responded to the recommendations. We estimate these potential health impacts using recent pollution data in three U.S. locations: Denver, Colorado; Los Angeles, California; and Pittsburgh, Pennsylvania. We focus on mortality risks among the elderly, who are particularly vulnerable. Under the strong assumptions of no infiltration and no offsetting indoor sources, we estimate that the benefits associated with avoiding ambient ozone and fine particle exposure are generally less than $14 per person for one additional hour spent indoors on days when air quality thresholds are exceeded. These estimates are sensitive to assumptions regarding the relationship between decreased exposure and mortality risks. Individuals' decisions to stay indoors likely depend on the value of the health benefits compared with the value of forgone work and leisure activities. While the national warning system provides flexibility and allows individuals to tailor their responses to personal circumstances, our analysis suggests that its benefits under typical conditions are small. The benefits of warnings under wildfire or other extreme conditions may be much greater.

Chemical characterization and source apportionment of fine and coarse atmospheric particulate matter in Doha, Qatar

Atmospheric particulate matter of two size fractions (i.e., PM2.5 and PM10) were sampled simultaneously at an urban site in Doha, Qatar, and characterized to measure chemical constituents (including trace elements, organic and elemental carbon (OC/EC), and water-soluble ions). The composition data were applied to mass closure analysis and Positive Matrix Factorization (PMF) model along with detailed wind direction analysis for quantifying and identifying the probable sources of both PM size fractions. The average concentrations of PM2.5 (40 μg m−3) and PM10 (146 μg m−3) were greatly exceeded the WHO air quality thresholds for 78–92% of the sampling days. Mass closure indicated the predominance of secondary inorganic aerosol (39%) and EC (7%) in fine PM, while mineral dust contributes 50% to the total mass of coarse particles. PMF identified six major sources of fine and coarse PM, including secondary inorganic aerosols, vehicular emissions, heavy oil combustion, marine aerosols, mineral and fugitive dust. The wind direction analysis indicated that both local and regional sources impact Qatar's air quality attributed to specific wind conditions. Two main sources of heavy oil combustion and secondary aerosols are closely related to regional emissions from shipping vessels and the petrochemical industry in the Gulf region. The desert dust transport mixed with local re-suspended dust and sea-salt particles also contributes considerably to the local PM concentrations. The significant contributions of regional anthropogenic and natural emissions pose a significant challenge in meeting local PM standards, signifying the importance of regional collaboration for better control policies on reducing transboundary air pollution.

Short term association between air pollution (PM10, NO2 and O3) and secondary spontaneous pneumothorax

Secondary spontaneous pneumothorax (SSP) occurs in the context of underlying pulmonary disease. Our objectives were to estimate the relationship between SSP and short term air pollution exposure with nitrogen dioxide (NO2), ozone (O3) and particulate matter with a diameter ≤ 10 μm (PM10). Patients with SSP were included between June 1, 2009 and May 31, 2013, in 14 Emergency Departments in France. In this case–crossover design study, PM10, NO2, and O3 data were collected hourly from monitoring stations. Quantitative values, fast increase in air pollutant concentration, and air quality threshold exceedance were retained. These assessments were calculated for each of the 4 days prior to the event (Lag 1–Lag 4) for all case and control period, and for the entire exposure period. A total of 135 patients with SSP were included, with a mean age of 55.56 (SD 18.54) years. For short term exposure of PM10, NO2 and O3, no differences were observed between case and control periods in terms of quantitative values of air pollutant exposure (P > 0.68), fast increase in concentration (P > 0.12) or air quality threshold exceedance (P > 0.68). An association between O3 exposures cannot be ruled out, especially when considering the Lag 2 prior to the event and in warm seasons.

The long-term impact of restricting cycling and walking during high air pollution days on all-cause mortality: Health impact Assessment study

Regular active commuting, such as cycling and walking to and from the workplace, is associated with lower all-cause mortality through increased physical activity (PA). However, active commuting may increase intake of fine particles (PM2.5), causing negative health effects. The purpose of this study is to estimate the combined risk of PA and air pollution for all-cause mortality among active commuters who, on days with high PM2.5 levels, switch to commuting by public transportation or work from home. Towards this purpose, we developed a Health Impact Assessment model for six cities (Helsinki, London, Sao Paulo, Warsaw, Beijing, New Delhi) using daily, city-specific PM2.5 concentrations. For each city we estimated combined Relative Risk (RR) due to all-cause mortality for the PA benefits and PM2.5 risks with different thresholds concentrations. Everyday cycling to work resulted in annual all-cause mortality risk reductions ranging from 28 averted deaths per 1000 cyclists (95% confidence interval (CI): 20–38) in Sao Paolo to 12 averted deaths per 1000 cyclists (95% CI: 5–19) in Beijing. Similarly, for everyday walking, the reductions in annual all-cause mortality ranged from 23 averted deaths per 1000 pedestrians (95 CI: 16–31) in Sao Paolo to 10 averted deaths per 1000 pedestrians (95%CI: 5–16) in Beijing. Restricting active commuting during days with PM2.5 levels above specific air quality thresholds would not decrease all-cause mortality risk in any examined city. On the contrary, all-cause mortality risk would increase if walking and cycling are restricted in days with PM2.5 concentrations below 150 μg/m3 in highly polluted cities (Beijing, New Delhi). In all six cities, everyday active commuting reduced all-cause mortality when benefits of PA and risk or air pollution were combined. Switching to working from home or using public transport on days with high air pollution is not expected to lead to improved all-cause mortality risks.

Bayesian geostatistical modelling of high-resolution [formula omitted] exposure in Europe combining data from monitors, satellites and chemical transport models

Bayesian geostatistical regression (GR) models estimate air pollution exposure at high spatial resolution, quantify the prediction uncertainty and provide probabilistic inference on the exceedance of air quality thresholds. However, due to high computational burden, previous GR models have provided gridded ambient nitrogen dioxide (NO2) concentrations at smaller areas of investigation. Here, we applied these models to estimate yearly averaged NO2 concentrations at 1 km2 spatial resolution across 44 European countries, integrating information from in situ monitoring stations, satellites and chemical transport model (CTM) simulations. The tropospheric values of NO2 derived from the ozone monitoring instrument (OMI) onboard the National Aeronautics and Space Administration’s (NASA’s) Aura satellite were converted to near ground NO2 concentration proxies using simulations from the 3-D global CTM (GEOS-Chem) at 0.5° × 0.625°spatial resolution and surface-to-column NO2 ratios. Simulations from the Ensemble of regional CTMs at spatial resolution of 0.1° × 0.1°were extracted from the Copernicus atmosphere monitoring service (CAMS). The contribution of these covariates to the predictive capability of geostatistical models was for the first time evaluated here through a rigorous model selection procedure along with additional continental high-resolution satellite-derived products, including novel data from the pan-European Copernicus land monitoring service (CLMS). The results have shown that the conversion of columnar NO2 values to surface quasi-observations yielded models with slightly better predictive ability and lower uncertainty. Nonetheless, the use of higher resolution CAMS-Ensemble simulations as covariates in GR models granted the most accurate surface NO2 estimates, showing that, in 2016, 16.17 (95% C.I. 6.34–29.96) million people in Europe, representing 2.97% (95% C.I. 1.16% - 5.50%) of the total population, were exposed to levels above the EU directive and WHO air quality guidelines threshold for NO2. Our estimates are readily available to policy makers and scientists assessing the burden of disease attributable to NO2 in 2016.

Spatial and Temporal Variations in SO2 and PM2.5 Levels Around Kīlauea Volcano, Hawai'i During 2007–2018

Among the hazards posed by volcanoes are the emissions of gases and particles that can affect air quality and damage agriculture and infrastructure. A recent intense episode of volcanic degassing associated with severe impacts on air quality accompanied the 2018 lower East Rift Zone (LERZ) eruption of Kīlauea volcano, Hawai'i. This resulted in a major increase in gas emission rates with respect to usual emission values for this volcano, along with a shift in the source of the dominant plume to a populated area on the lower flank of the volcano. This led to reduced air quality in downwind communities. We analyse open-access data from the permanent air quality monitoring networks operated by the Hawai'i Department of Health (HDOH) and National Park Service (NPS), and report on measurements of atmospheric sulfur dioxide (SO2) between 2007 and 2018 and PM2.5 (aerosol particulate matter with diameter <2.5 μm) between 2010 and 2018. Additional air quality data were collected through a community-operated network of low-cost PM2.5 sensors during the 2018 LERZ eruption. From 2007 to 2018 the two most significant escalations in Kīlauea's volcanic emissions were: the summit eruption that began in 2008 (Kīlauea emissions averaged 5–6 kt/day SO2 from 2008 until summit activity decreased in May 2018) and the LERZ eruption in 2018 when SO2 emission rates reached a monthly average of 200 kt/day during June. In this paper we focus on characterizing the airborne pollutants arising from the 2018 LERZ eruption and the spatial distribution and severity of volcanic air pollution events across the Island of Hawai'i. The LERZ eruption caused the most frequent and severe exceedances of the Environmental Protection Agency (EPA) PM2.5 air quality threshold (35 μg/m3 as a daily average) in Hawai'i in the period 2010–2018. In Kona, for example, the maximum 24-h-mean mass concentration of PM2.5 was recorded as 59 μg/m3 on the twenty-ninth of May 2018, which was one of eight recorded exceedances of the EPA air quality threshold during the 2018 LERZ eruption, where there had been no exceedances in the previous 8 years as measured by the HDOH and NPS networks. SO2 air pollution during the LERZ eruption was most severe in communities in the south and west of the island, as measured by selected HDOH and NPS stations in this study, with a maximum 24-h-mean mass concentration of 728 μg/m3 recorded in Ocean View (100 km west of the LERZ emission source) in May 2018. Data from the low-cost sensor network correlated well with data from the HDOH PM2.5 instruments, confirming that these low-cost sensors provide a robust means to augment reference-grade instrument networks.

Impact of port emissions on EU-regulated and non-regulated air quality indicators: The case of Civitavecchia (Italy)

Current shipping activities employ about 3% of the world-delivered energy. Most of this energy is conveyed by diesel engines. In Europe, release of NOx and particulate matter (PM) from shipping is expected to equal the road-transport one by the year 2020. This paper addresses a typical central Mediterranean city-port condition to evaluate the relative contribution of shipping activities to the local air quality. A 3-year long air quality dataset collected at the boundary between the port of Civitavecchia (the major port in central Italy) and the city itself was analyzed to evaluate the long-term, relative contribution of the port and of the city at determining the loads of EU-regulated pollutants (NO2, PM10 and SO2). In addition, black carbon and ultrafine-to-coarse particles data collected along a short-term, intensive campaign were used to assess the port’s role at emitting these unregulated pollutants. Cross-analysis of the measurements, allowed to assess which shipping-related activities and port’s sectors represent the principal emitters. At the city-port boundary, the annual share of regulated pollutants originating in the port area by shipping and ground movements is of 33% for PM10, 43% for NO2, and 60% for SO2. Analysis of non-regulated pollutants shows the in-port, high polluting potential of some ship categories, in particular those employing low-sulfur but poorly refined oils. These conditions appear to be more often associated with Ro-Ro passenger ships. Piers closest to the Civitavecchia urban settlements are also observed to host the largest emissions. Meteorology and location of the piers with respect to residential areas are confirmed to govern the port’s share at impacting the city air quality. Even though air quality thresholds for regulated pollutants are not exceeded in Civitavecchia, constant consideration of an enlarged set of environmental variables should drive actions implemented to mitigate the port’s impact onto the nearby city’s air quality.

Computation and Assessment of Environmental Emissions Resulting from Traffic Operations at Roundabouts

Now recognised as a dangerous side effect of increasing human activity and particularly the use of fossil fuels, is the impact on air quality, which has deteriorated considerably in recent times. In particular, the dramatic rise in road traffic has driven up the levels of air pollution in our towns and cities, leading to serious problems for both public health and the environment. To redress this, Environment Policies developed by the World Health Organisation (WHO) and European Commission (EC) have identified clean air as an essential requirement to human health and for the environment – a human right. Therefore, the need for managing emissions resulting from road traffic has seen significant attention. Coincidentally, the increases in the last decades of computational ability has enabled rapid development of transport modelling tools that can be integrated with environmental emissions packages. This has led to the increased ability to test the impact of road emissions on public health and environment. The computational ability to analyse the impact of traffic conditions for both current and forecast operations has enabled engineers to identify improved management and operation techniques for the road intersections with a view to reduce the emissions’ impact. This study presents a new and innovative approach to inform such forecast emissions, representing an approach to develop designs that can reduce emissions by linking various software packages as demonstrated at a trial site at a road intersection at Bath, United Kingdom. The technique linked the transport micro-simulation tool VISSIM with the environmental software EnViVer for emissions analysis. The models are also linked to Geographic Information System software, QGIS, to display changing levels of NOx, CO 2 and PM (Particulate Matter) under alternative intersection operational management regimes. This approach has enabled three important outcomes: 1) development of a methodology to directly test emissions and inform air quality thresholds using a series of software tools in an integrated manner, 2) enable the investigation of the air quality outcomes for alternative intersection designs and 3) to produce functions for intersection operational parameters that can predict NO X , CO 2 and PM savings. The results have demonstrated that the linking of the computational ability of micro-simulation modelling of road intersections with environmental package has been successful in analysis of operations. The ‘combined’ modelling approach has enabled design development of future intersection operation to with a view to minimising NO X , CO 2 and PM. This approach has brought together the crucial traffic parameters of road speed, delay and queuing and related them directly to change in emissions formulation, with the evidenced based prospect of adoption for similar studies in future. To put numbers to the achievement, the results have shown significant achievements for both the NO X level, which is projected to reduce by 14-34%, CO 2 by over 13-32% and PM by over 14-26% compared with the base conditions.