High Traffic Sites Research Articles

Ocean soundscapes reveal climatic and economic oscillations

An accumulation of 26 859 days of acoustic recordings (spanning over 74 years at six sites) was processed and analyzed to investigate the interannual, seasonal, and diel patterns within six ocean soundscapes. Biological sound levels (18-25 Hz and 40–45 Hz) quantified acoustic energy from fin and blue whales, ambient sound levels (63-Hz and 800-Hz one-third-octave) quantified energy from ships and wind, and broadband spectra (15 Hz to 1 kHz) identified changes across time and space. Biological sound levels varied seasonally and correlated with large-scale climatic patterns and long-term ocean fluctuations. During marine heatwaves, baleen whale associated sound levels decreased in southern sites and increased in sites adjacent to the California Current. Ship sound levels at high-traffic sites reflected economic events such as the financial crisis, labor shortages and negotiations, and changes to port flows. Wind speeds and associated sound levels reflected on-shore/off-shore relationships and decreased during the morning hours. Understanding marine soundscapes aids in understanding the ocean’s ecological health amidst the ever-changing impact of climate change.

Using date palm (Phoenix dactylifera L.) as bio-monitors of environmental quality for exposure assessment and pollution source tracking

Using date palm (Phoenix dactylifera L.) as bio-monitors of environmental quality for exposure assessment and pollution source tracking

Seasonal and diurnal measurement of ambient benzene at a high traffic inflation site in Delhi: Health risk assessment and its possible role in ozone formation pathways.

Benzene is the most toxic and hazardous pollutant among volatile organic compounds (VOCs), as it comes under group 1 carcinogens recognized by the International Agency for Research on Cancer (IARC). It also plays a significant role in forming secondary pollutants like ozone. The benzene concentration was measured using a charcoal sorbent tube by active sampling at a traffic junction and analysis was done using GC-FID. The maximum average concentration of benzene in ambient air was found to be 33 μg/m3. A diurnal study of benzene measurement shows higher benzene concentrations in the evening compared to the morning. Seasonal variation of benzene is found to be winter > spring > summer > autumn > monsoon and OFP was found to be 21, 19, 14, 13, and 10 respectively. Cancer (ILCR) and non-cancer (HQ) health risk assessment was done to determine the impact of ambient benzene on the residents of urban areas. The yearly average value of ILCR was found to be 2×10-6 ± 1×10-6 which ranges from acceptable value to three times the WHO acceptable value i.e 1×10-6. The correlation of ozone and its precursor, benzene with meteorological parameters is also evaluated. The correlation of benzene and ozone with solar radiation shows the influence of photochemical reactions on the levels of benzene and ozone at the study site, although it is low.

Impact of traffic-related air pollution on the blood pressure response to exercise in individuals with hypertension

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Natural Sciences and Engineering Research Council of Canada and B.C. Sports & Exercise Medicine Research Foundation. Background The epidemiologic evidence suggests that the health benefits of exercise in healthy adults outweigh the adverse effects of air pollution in all but the most extreme concentrations. However, no studies have examined the acute response to exercise in air pollution in individuals with hypertension, a subgroup particularly susceptible to the cardiovascular effects of air population. Purpose The purpose of this study was to determine the impact of traffic-related air pollution on the acute cardiovascular response to exercise in patients with hypertension. We hypothesized that exposure to higher levels of traffic-related air pollution during exercise would attenuate, but not eliminate, acute post-exercise reductions in blood pressure and arterial stiffness. Methods Fourteen patients with hypertension (62.4±6.8 years; 81% male) completed a real-world, randomized, crossover study. Two 30-minute exercise bouts at 40-59% heart rate reserve were performed: once along a commercial street (high traffic) and once in an urban plaza (low traffic). Blood pressure (BP) and arterial stiffness (i.e., carotid-femoral pulse wave velocity [cfPWV]) were examined prior to, 30 minutes after, and 2 hours following exercise. 24-hour ambulatory BP monitoring was immediately completed following each visit. Black carbon, noise, relative humidity, and temperature were measured during each exercise bout (Figure 1). Results No differences were found for baseline cardiovascular measures between high and low traffic visits. At 30 minutes and 2 hours post-exercise, systolic BP was significantly reduced relative to baseline in the low-traffic condition only; diastolic BP was not significantly reduced at any timepoint. Based on linear mixed-effects analyses, exercising at the low traffic site was associated, relative to the high traffic site, with a significant (p = 0.04) reduction in systolic BP (-4.30 mm Hg [95% CI -8.09 to -0.54]) up to 2 hours following exercise after adjusting for exercise intensity, temperature, and noise; no differences were found for diastolic BP (-1.56 mm Hg [95% CI -4.87 to 1.83], p = 0.39). Each interquartile increase in black carbon (1168 ng/m³) was significantly associated with a 2.33 mm Hg (95% CI 0.37 to 4.17) increase in systolic BP up to 2 hours following exercise. No associations were observed between traffic site and BP for any ambulatory periods (i.e., 24-hour average, daytime, nighttime, or evening). The acute cfPWV response to exercise was also similar between traffic sites (p > 0.05). Conclusion Our findings suggest that exposure to traffic-related air pollution during exercise may adversely impact the beneficial short-term BP response to exercise in patients with hypertension. While the long-term implications of these changes to the acute BP response to exercise must be further explored, patients with hypertension can employ the prudent strategy of maximizing their distance from major roadways when exercising.

Visual surveys provide baseline data on small vessel traffic and waterbirds in a coastal protected area.

The coastal waters of southern British Columbia, Canada, encompass habitat of international conservation significance to coastal and marine birds, including sizeable areas designated in the early 1900s as Migratory Bird Sanctuaries (MBS) to protect overwintering waterfowl from hunting near urban centres. Two of these, Shoal Harbour (SHMBS) and Victoria Harbour (VHMBS), have seen significant marine infrastructure development in recent decades and experience considerable vessel traffic. Vessel-related stressors are known to affect waterbirds, but traffic characteristics in coastal urban areas are poorly understood for the smaller vessels not tracked by Automatic Identification Systems (AIS). We conducted a pilot study using shore-based observers to develop small-vessel baselines for the winter months, when regional waterbird numbers are highest. During our surveys we recorded considerable inter-site variability in vessel traffic characteristics, with one site (SHMBS) a source of nearly twice as many vessel transits as the other (VHMBS). Most recorded vessels were small watercraft (mean length 26 ± 17', mode 18'), and vessels at the high-traffic site were both shorter and faster on average. One in six vessels were classified as 'noisy', of interest given that noise is an important component of vessel disturbance of waterbirds and other marine animals. Few vessels (7% of all recorded) were of the type required to carry AIS transponders, which highlights the monitoring gap created by using AIS-based approaches alone in nearshore waters, and allows for correction of AIS-derived vessel counts. Waterbird community composition also varied by locality, with one site dominated by gulls (Laridae), cormorants (Phalacrocoracidae), and seaducks (Tribe Mergini), and the other by gulls, cormorants, and alcids (Alcidae). Our results demonstrate that fine-scale local variability must be taken into account when managing for vessel traffic disturbance of waterbirds, particularly at sites of high human population density and increasing coastal development.

Traffic Density and Air Pollution: Spatial and Seasonal Variations of Nitrogen Dioxide and Ozone in Jamaica, New York

Nitrogen dioxide (NO2) and ground-level ozone (O3) pose significant public health concerns in urban areas. This study assessed the safety level of NO2 and described spatial and seasonal variations of NO2 and O3 in Jamaica Center, New York, using low-cost diffusion tubes at six high-traffic (HT) and three low-traffic (LT) sites over two-week intervals in summer, winter, and fall of 2019. When annualized, the highest NO2 level (33.90 μg/m3) was below the safety threshold (99.6 μg/m3). Mean concentrations of NO2 samples were significantly higher at HT sites (35.79 μg/m3; 95%CI: 32.81–38.77) compared to LT sites (25.29 μg/m3; 95%CI: 11.73–28.85), p = 0.002, and during fall (38.14 μg/m3; 95%CI: 31.18–45.11) compared to winter (25.53 μg/m3; 95%CI: 20.84–30.22). There was no significant difference in O3 levels between the fall (51.68 μg/m3; 95%CI: 44.70–58.67) and summer (46.43 μg/m3; 95%CI: 35.25–57.61), p = 0.37, and between HT sites (48.51 μg/m3; 95%CI: 40.39–56.63) and LT sites (50.14 μg/m3; 95%CI: 43.98–56.30), p = 0.79. Our results demonstrate the feasibility of low-cost air monitoring and the need for emission control policies along major corridors mainly in fall and summer, especially with the rapid commercial and economic development underway in Jamaica Center.

Tobacco-free policy reduces combustible tobacco byproduct on a large university campus.

Policy drives community-level behavior change, so behavior analysts should aid empirical policy development. University campus regulation is a useful proxy for broader policy initiatives and thus is a convenient inroad for behavior analyst involvement. This paper examines behavior analytic contributions to the planning and evaluation of a university tobacco-free initiative. We provided resources and guidance throughout early planning, and we then evaluated faculty and student compliance via byproduct (e.g., cigarette butts) counts taken at four high-traffic sites (as flagged by preliminary surveying of campus faculty, staff, and students). Visual analysis and supplementary statistical testing support notions of (a) a meaningful and sustained reduction of combustible tobacco byproducts in all locations, and (b) a demonstrative example of behavior analytic involvement with university policy planning and evaluation.

Temporal and spatial biomonitoring of atmospheric heavy metal pollution using moss bags in Xichang

Heavy metal air pollution poses a serious threat to human health and the environment in Chinese tourist cities. In this study, we investigated the temporal and spatial variations of atmospheric heavy metal pollution using moss bags in Xichang, a tourist destination in Southwest China. The biomonitoring investigation used an indigenous moss (Taxiphyllum taxirameum) transplanted into bags. Moss bags were exposed to 22 sites including industrial, agricultural, urban/residential, tourist, and high-traffic sites, across four different seasons in 2019-2020. The results showed that T. taxirameum was a good biomonitor of air pollution in Xichang. Among the 22 sample points, air pollution was the worst along the G102 motorway. Heavy metal emissions varied in different regions and directions. Temporal changes significantly influenced the heavy metals accumulated in moss bags, with low deposition of most elements observed at nearly all sampling sites in summer. Different seasons and regions were important factors affecting atmospheric heavy metal pollution. Based on the correlation analysis and the positive matric factorization model, the results revealed that heavy metals in moss bags in Xichang were mainly derived from anthropogenic sources and atmospheric deposition. Overall, this research provides an important reference for air pollution monitoring in urban areas.

On the application and grid-size sensitivity of the urban dispersion model CAIRDIO v2.0 under real city weather conditions

Abstract. There is a gap between the need for city-wide air-quality simulations considering the intra-urban variability and mircoscale dispersion features and the computational capacities that conventional urban microscale models require. This gap can be bridged by targeting model applications on the gray zone situated between the mesoscale and large-eddy scale. The urban dispersion model CAIRDIO is a new contribution to the class of computational-fluid dynamics models operating in this scale range. It uses a diffuse-obstacle boundary method to represent buildings as physical obstacles at gray-zone resolutions in the order of tens of meters. The main objective of this approach is to find an acceptable compromise between computationally inexpensive grid sizes for spatially comprehensive applications and the required accuracy in the description of building and boundary-layer effects. In this paper, CAIRDIO is applied on the simulation of black carbon and particulate matter dispersion for an entire mid-size city using a uniform horizontal grid spacing of 40 m. For model evaluation, measurements from five operational air monitoring stations representative for the urban background and high-traffic roads are used. The comparison also includes the mesoscale host simulation, which provides the boundary conditions. The measurements show a dominant influence of the mixing layer evolution at background sites, and therefore both the mesoscale and large-eddy simulation (LES) results are in good agreement with the observed air pollution levels. In contrast, at the high-traffic sites the proximity to emissions and the interactions with the building environment lead to a significantly amplified diurnal variability in pollutant concentrations. These urban road conditions can only be reasonably well represented by CAIRDIO while the meosocale simulation indiscriminately reproduces a typical urban-background profile, resulting in a large positive model bias. Remaining model discrepancies are further addressed by a grid-spacing sensitivity study using offline-nested refined domains. The results show that modeled peak concentrations within street canyons can be further improved by decreasing the horizontal grid spacing down to 10 m, but not beyond. Obviously, the default grid spacing of 40 m is too coarse to represent the specific environment within narrow street canyons. The accuracy gains from the grid refinements are still only modest compared to the remaining model error, which to a large extent can be attributed to uncertainties in the emissions. Finally, the study shows that the proposed gray-scale modeling is a promising downscaling approach for urban air-quality applications. The results, however, also show that aspects other than the actual resolution of flow patterns and numerical effects can determine the simulations at the urban microscale.

Correction: Sadiq et al. A Characterization and Cell Toxicity Assessment of Particulate Pollutants from Road Traffic Sites in Kano State, Nigeria. Atmosphere 2022, 13, 80

Emerging African countries are characterized by explosive population growth and urbanization, which threaten environmental sustainability. This study comparatively characterized ambient aerosols and assessed cytotoxicity to facilitate improving health and environmental policy. Twenty-four air samples were collected at high and low-density traffic sites in Kano State using polysulfone and stainless steel filters attached to an automated pump. The physico-chemical properties of particulate matter were determined using scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDX). In vitro, their potential toxicity was assessed using macrophages and cell fixation with staining. Results showed 51.7% of particles as PM2.5, with the highest particle concentration in mixed sites (urban and industrial). Particle classification into four groups by elemental composition and structure showed: sand particles (Si, Al, Fe, Ca, Mg, K, Na, Mo, Sr, Zr) 30–51%; other fibers 0–3%; other particles (Si, Fe, S, Mo, Zn, and other metals) 22–40%; and silicone-based fibres 23–34%. The abundant elements are: Si, Al, Ca, Ce, Ti, Fe, Cl, Pb, and Mn. The lowest viability on cytotoxicity assessment was recorded in mixed site M2. The majority of households were located within 50 m of air sampling sites. Proximity to traffic sites worsens health, as evidenced in cytotoxicity findings. We recommend improved urban planning and intensification of emissions control.

Road Runoff Characterization: Ecotoxicological Assessment Combined with (Non-)Target Screenings of Micropollutants for the Identification of Relevant Toxicants in the Dissolved Phase

Road runoff (RR) is an important vector of micropollutants towards groundwater and soils, threatening the environment and ecosystems. Through combined chemical and biological approaches, the purpose of this study was to get insights on specific toxicants present in RR from two sites differing by their traffic intensity and their toxicological risk assessment. Non-target screening was performed by HRMS on RR dissolved phase. Ecotoxicological risk was evaluated in a zebrafish embryos model and on rat liver mitochondrial respiratory chain. Specific HRMS fingerprints were obtained for each site, reflecting their respective traffic intensities. Several micropollutants, including 1,3-diphenylguanidine (DPG) and benzotriazole (BZT) were identified in greater concentrations at the high-traffic site. The origin of DPG was confirmed by analyzing HRMS fingerprints from shredded tires. RR samples from each site, DPG and BZT were of relatively low toxicity (no mortality) to zebrafish embryos, but all generated distinct and marked stress responses in the light–dark transition test, while DPG/BZT mixes abolished this effect. The moderate-traffic RR and DPG inhibited mitochondrial complex I. Our study highlights (i) the unpredictability of pollutants cocktail effect and (ii) the importance of a multi-approaches strategy to characterize environmental matrices, essential for their management at the source and optimization of depollution devices.

A Characterization and Cell Toxicity Assessment of Particulate Pollutants from Road Traffic Sites in Kano State, Nigeria

Emerging African countries are characterized by explosive population growth and urbanization, which threaten environmental sustainability. This study comparatively characterized ambient aerosols and assessed cytotoxicity to facilitate improving health and environmental policy. Twenty-four air samples were collected at high and low-density traffic sites in Kano State using polysulfone and stainless steel filters attached to an automated pump. The physico-chemical properties of particulate matter were determined using scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDX). In vitro, their potential toxicity was assessed using macrophages and cell fixation with staining. Results showed 51.7% of particles as PM2.5, with the highest particle concentration in mixed sites (urban and industrial). Particle classification into four groups by elemental composition and structure showed: sand particles (Si, Al, Fe, Ca, Mg, K, Na, Mo, Sr, Zr) 30–51%; other fibers 0–3%; other particles (Si, Fe, S, Mo, Zn, and other metals) 22–40%; and silicone-based fibres 23–34%. The abundant elements are: Si, Al, Ca, Ce, Ti, Fe, Cl, Pb, and Mn. The lowest viability on cytotoxicity assessment was recorded in mixed site M2. The majority of households were located within 50 m of air sampling sites. Proximity to traffic sites worsens health, as evidenced in cytotoxicity findings. We recommend improved urban planning and intensification of emissions control.

Investigation of Ambient Polycyclic Aromatic Hydrocarbons in a Populated Middle Eastern City

Characteristics, sources and health risks of atmospheric PM10-bound polycyclic aromatic hydrocarbons (PAHs) on residents living in different regions of Ahvaz, Southwest Iran were investigated during 2016–2017. 84 samples were taken from the different regions: (S1) industrial; (S2) high traffic and (S3) residential sites in Ahvaz metropolitan. Urinary samples were collected from people who came to the east health center of Ahvaz. Urinary 1-hydroxypyrene and PAHs levels were analyzed by Gas Chromatography with Mass Spectrometry (GC/MS). Exposure and risk assessment (Incremental Lifetime Cancer Risk (ILCR), Lifetime Average Daily Dose (LADD) and hazard index (HI)) of these pollutants were estimated, using USEPA’s exposure parameters. Results of this study showed that in the air of residential and industrial areas observed the lowest and the highest level of PAHs, respectively. High molecular weight compounds (2–4rings), contributed to 85% of ∑PAHs mass in the atmospheric PM10-bound samples. Industrial processing and petroleum refining, were identified to be major outdoor resources of PAHs. Based on the result of this study, the highest and the lowest concentration of PAHs metabolites were observed in the industrial and residential areas. Average urinary 1-hydroxypyrene levels of S1, S2 and S3 regions were 0.4735; 1.311 and 1.4942 ng/dL, respectively. The values of ILCR in cold (0.06913) and warm (0.052854) seasons were higher than EPA which, was significantly correlated with the concentration of PAHs. In conclusion, increasing exposure concentration of polycyclic aromatic hydrocarbons would have a significant potential for increased ILCR and risk of health endpoint. ILCR in different areas was significantly higher than standard. Our results show that the air quality of Ahvaz city was in an unfavorable condition and increasing exposure concentration of PAHs would have a significant potential for increased ILCR and risk of diseases.

Knowledge of osteopathic manipulative medicine and osteopathic physicians in a New York South Asian community.

Research regarding patient awareness of osteopathic manipulative medicine (OMM) can help identify barriers and factors limiting patient knowledge. Levels of knowledge about OMM and osteopathic physicians have been studied in New York's Chinese and Korean populations, but have not previously been investigated in the South Asian population. To assess the knowledge of OMM and osteopathic physicians within a South Asian community of New York. A cross-sectional study was designed in which a culturally appropriate survey, provided in both English and Hindi, was administered to study participants in order to measure knowledge of osteopathic medicine. The study utilized convenience sampling and distributed surveys to individuals who identified themselves of South Asian descent at high traffic sites in Hicksville, New York. The survey contained 10 questions, assessing the individual's knowledge of osteopathic medicine. The Kruskal-Wallis and Chi-Square tests were employed to determine statistical significance of the data obtained from the surveys. The survey was conducted on 100 participants inHicksville, New York. The respondent demographics included 53 males and 47 females with an average age of 41.2±16.3 years old. There were 34 (34%) participants who had heard of osteopathic manipulative medicine (OMM) and 26 (26%) participants who had knowledge of doctor of osteopathic medicine (DO) physicians. Respondents were found more likely to have knowledge of DOs if they were born in the United States (US) vs. other countries (US, 8 of 14 [57.1%] vs. others, 18 of 86 [20.9%]; p=0.006) or lived longer in the US (11 of 26 [42.3%], p=0.039). Participants who spoke a non-English primary language were also found less likely to have knowledge of DOs as they made up 46 of the 58 respondents who indicated no knowledge (79.3%, p=0.042). A general lack of knowledge of DOs and OMM exists within the South Asian community of Hicksville, New York and lower levels of awareness were found among participants who were male, born outside the US, had a language other than English as their primary language, and had spent less time in the US. Additional educational resources may be implemented to increase awareness of DOs and OMM among this and similar communities.

Pollution and health risk assessment of arsenic in street dust and soil from an industrial zone

Taking an industrial area in Wuhan as the research object, single factor index, Geoaccumulation index and EPA health risk model are utilized to evaluate the pollution pattern and health risk of arsenic (As) in street dust with different particle fractions and soil. The results showed that the content of As in street dust increased with the decrease of particle size. The average content of As in street dust with fine particle fraction and soil exceeded the soil background value of Hubei Province, but did not exceed the screening value of “Soil Environmental Quality Construction Site Soil Pollution Risk Control Standards (Trial)”. The content of As in soil had a high correlation with that of dust with < 63 particle fraction at the corresponding point, with high fit degree (R2=0.6012). There was moderate to heavy pollution of As in areas surrounding industrial enterprises like Wuhan Iron and Steel, cement plants, and areas with high traffic flow and construction sites. The As of street dust and soil at some points posed a non-carcinogenic risk to children, but no carcinogenic risk. The ingestion pathway was the largest non-carcinogenic exposure route of As in street dust and soil from the research area.

Metal Accumulation Capability by &amp;lt;i&amp;gt;Platanus acerifolia&amp;lt;/i&amp;gt; (Aiton) Willd., &amp;lt;i&amp;gt;Ailantus altissima&amp;lt;/i&amp;gt; (Mill.) Swingle, &amp;lt;i&amp;gt;Robinia pseudoacacia&amp;lt;/i&amp;gt; L. and &amp;lt;i&amp;gt;Quercus ilex&amp;lt;/i&amp;gt; L., Largely Distributed in the City of Rome

The main of the research was to analyze the leaf metal accumulation capability of Platanus acerifolia (Aiton) Willd., Ailantus altissima (Mill.) Swingle, Robinia pseudoacacia L. and Quercus ilex L., largely distributed in Rome. In addition, metal concentration was analyzed in the soil, sampling sites were chosen in historical parks (A sites) and high traffic level sites (B sites). The results highlight significant higher leaf and soil metal concentrations in B than in A sites. The ratio between metal concentration in leaves and soils (Biological Absorption Coefficient, BAC) for all the considered sites was significantly different among the species. Morphological and anatomical leaf traits of the considered species show significant differences in A and B sites in response to traffic level. Overall, the results highlight the importance of the selection of tree species in urban areas for their ability to lower pollution levels.

Environmental monitoring of toxic metals in roadside soil and dust in Ulsan, South Korea: pollution evaluation and distribution characteristics

This study investigated toxic metal distribution in roadside soil and dust in the metropolitan city of Ulsan, South Korea, and the factors affecting distribution, using Korean waste-leaching tests, determination of total concentrations, sequential extraction, and statistical analysis. Composite grab samples were collected from high-traffic roads (7 sites), low-traffic roads (2 sites), and an uncontaminated control area (2 sites) in Ulsan. The pH of roadside soil and dust was slightly alkaline. The concentrations of copper, lead, and zinc in soil as determined by Korean waste-leaching tests decreased as soil depth increased, while those of arsenic, nickel, and chromium increased. Leaching concentrations in dust were lower than in soil, with the exception of copper. Total concentrations decreased as soil depth increased, and total concentrations of metals in dust were higher than in soil. The sampling sites that exceeded the regulation levels of soil contamination in South Korea were 7 points in topsoil, 3 points in middle soil, and 9 points in dust. TCLP tests showed that the concentrations of arsenic, cadmium, and lead in topsoil and dust at Duwang and Myeongchon intersections were higher than regulatory levels. The maximum correlation coefficient among two metals in soil and dust was 0.987 (p < 0.01), for cadmium and lead. Concentrations of cadmium, copper, arsenic, lead, nickel, and mercury, mostly from tire and brake-pad abrasion, were highly correlated. The strong positive correlation between traffic volume and metals in dust suggests that vehicle emissions may be responsible for metal contamination of soil and dust. Pollution indices of topsoil at 4 sites and all dust at 7 high-traffic sites were higher than 1.0, which is consistent with an effect of vehicle traffic on metal contamination in soil and dust.

A survey of heavy metal contents of rural and urban roadside dusts: comparisons at low, medium and high traffic sites in Central Scotland.

Roadside dust can contain particulates enriched with potentially toxic elements (PTEs) as a result of the degradation of mechanical vehicular parts, tyre wear and combustion processes. To assess the potential accumulation of these metals in roadside areas, a snapshot study was carried out, investigating metal content at rural and urban locations in central Scotland. Samples of road dust were collected at six sites representing low, medium and high traffic intensity at rural and urban locations. The samples were separated based on particle size and analysed for heavy metal content using inductively coupled plasma optical emission spectroscopy (ICP-OES) after acid digestion. The metals analysed were aluminium (Al), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), lead (Pb) and zinc (Zn). The rural area measurements were carried out in West Lothian, approximately 13 to 17miles west of the city of Edinburgh (UK). The urban area measurements were carried out in the southern part of the Edinburgh city district (UK). Concentrations of Cu, Cr and Zn were found to correlate with traffic intensity, although only Cu and Zn concentrations exceed recommended EC directive 86/278/EEC guidelines for urban runoff materials. The metal concentrations of small particles (0.45-20μm) were exceedingly high in both Cu and Zn at areas of high traffic intensity, indicating potential areas of concern regarding health impacts for pedestrians and cyclists who are exposed to roadside dust on a regular basis.

Impacts of Modifiable Factors on Ambient Air Pollution: A Case Study of COVID-19 Shutdowns.

COVID-19-related closures offered a novel opportunity to observe and quantify the impact of activity levels of modifiable factors on ambient air pollution in real time. We use data from a network of low-cost Real-time Affordable Multi-Pollutant (RAMP) sensor packages deployed throughout Pittsburgh, Pennsylvania, along with data from Environmental Protection Agency regulatory monitors. The RAMP locations were divided into four site groups based on land use. Concentrations of PM2.5, CO, and NO2 following the COVID-related closures at each site group were compared to measurements from “business-as-usual” periods. Overall, PM2.5 concentrations decreased across the domain by ∼3 μg/m3. The morning rush-hour-induced CO and NO2 concentrations at the high-traffic sites were both reduced by ∼50%, which is consistent with observed reductions in commuter traffic (∼50%). The morning rush-hour PM2.5 enhancement from traffic emissions was reduced nearly 100%, from 1.4 to ∼0 μg/m3 across all site groups. There was no significant change in the industry-related intraday variability of CO and PM2.5 at the industrial sites following the COVID-related closures. If PM2.5 National Ambient Air Quality Standards (NAAQS) are tightened, this natural experiment sheds light on the extent to which reductions in traffic-related emissions can aid in meeting more stringent regulations.

Health risk assessment of polycyclic aromatic hydrocarbons (PAHs) adsorbed in PM2.5 and PM10 in a region of Arequipa, Peru.

The concentrations of PM2.5 and PM10, as well as those of the PAHs bound to these particles, were quantified at four sites in the region of Arequipa, Peru, during the year 2018. These samples were collected with high volume samplers, and the concentrations of the PAHs were quantified by liquid chromatography (HPLC). The values found for PM2.5 and PM10 at all the sampling sites in Arequipa exceeded the norms established in Peru (50 μg m-3 annual average value for PM10 and 25 μg m-3 annual average value for PM2.5), with the industrial site presenting the highest values of particulate matter (PM10 max = 235.1 μg m-3; PM2.5 max = 218.4 μg m-3). With respect to seasonality, in the cold season (winter), the concentration of particles was higher compared to the other seasons. Concerning the PAHs, it was found that these had the highest concentrations at the industrial site, followed by the site with high vehicular traffic, with both these sites differing significantly from the rural sites. In addition, at the industrial and high traffic sites, there was a predominance of PAHs with 5 and 6 rings, whereas at the rural sites, PAHs with fewer rings predominated. Finally, the calculated values of lifetime lung cancer risk also revealed a difference between sites with marked emission sources, where irrigation was considered moderate, and the rural sites, where irrigation was considered low. This demonstrated that people living at sites with mobile sources and/or industries had a higher cancer risk compared to the inhabitants of rural sites.