A significant concern for public health and visibility is airborne particulate matter, especially during extreme events. Of most relevance for health, air quality, and climate is the role of fine ...aerosol particles, specifically particulate matter with aerodynamic diameters less than or equal to 2.5 micrometers (PM2.5). The purpose of this study was to examine PM2.5 extreme events between 1989 and 2018 at Mesa Verde, Colorado using Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring data. Extreme events were identified as those with PM2.5 on a given day exceeding the 90th percentile value for that given month. We examine the weekly, monthly, and interannual trends in the number of extreme events at Mesa Verde, in addition to identifying the sources of the extreme events with the aid of the Navy Aerosol Analysis and Prediction (NAAPS) aerosol model. Four sources were used in the classification scheme: Asian dust, non-Asian dust, smoke, and “other”. Our results show that extreme PM2.5 events in the spring are driven mostly by the dust categories, whereas summertime events are influenced largely by smoke. The colder winter months have more influence from “other” sources that are thought to be largely anthropogenic in nature. No weekly cycle was observed for the number of events due to each source; however, interannual analysis shows that the relative amount of dust and smoke events compared to “other” events have increased in the last decade, especially smoke since 2008. The results of this work indicate that, to minimize and mitigate the effects of extreme PM2.5 events in the southwestern Colorado area, it is important to focus mainly on smoke and dust forecasting in the spring and summer months. Wintertime extreme events may be easier to regulate as they derive more from anthropogenic pollutants accumulating in shallow boundary layers in stagnant conditions.
The entry of potentially toxic elements (PTEs) into the environment has been raised as a problem for various countries. So, this study aimed to investigate the PTEs concentration in the environment. ...In this cross-sectional study, Ahvaz city, the capital city of Khuzestan province, was divided into 5 areas. At each site, three-date palms were selected. Leaves and mesh fibers samples were collected from the young palm (3 years) with a maximum trunk height of 3–4 m. Plant leaves samples were separated from the middle section of the main leaves area of the plant and mesh fibers were selected from the different parts of the palm data trunk (top, middle, and bottom of the palm data trunk on all four sides of the palm). Then, data palm samples were divided into two groups of washed/unwashed. Soil samples were collected from the closest point to the palms date at a depth of 0–50 cm including at two depths (0–20 cm and 20–40 cm), and then combined to make a composite soil sample. After the preparation of samples, PTEs were measured by ICP-OES. The highest PTEs concentrations were found in industrial and high-traffic sites and the lowest was obtained at the control site. The largest bioconcentration factor (BCF) was related to copper (2.34–7.49) in mesh fibers samples and in the leaves (1.65) in the control area. Principal component analysis (PCA) results showed metal(loid)s (copper, nickel, zinc, lead, iron, arsenic, and cobalt) are mostly related to brake wear and tire of vehicles and asphalt and road dust, while the metals (Manganese, chromium, and cadmium) mostly originate from industrial sources. Palm leaves, mesh fibers, and soil can be used as a cheap biomonitoring factor for PTEs analysis, especially in industrial and high-traffic regions.
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•Date palm leaves and mesh fibers shown to be low cost air quality monitors.•Potentially toxic elements (PTE) enriched in collected date palm samples.•Foliar data and PCA analysis help separate PTEs into sources (e.g., industrial, vehicles, dust).•Pollution source tracking was obtained using date palm (Phoenix dactylifera L.)
Air pollution is one of the leading causes of death from noncommunicable diseases globally, and in Arizona, both mining activities and abandoned agriculture can generate erodible dust. This dust is ...transported via wind and can carry high amounts of toxic pollutants. Industry-adjacent communities, or “fenceline communities,” are generally closer to the pollution sources and are disproportionally impacted by pollution, or in this case, dust. The dust transported from the mine settles into nearby rivers, gardens, and homes, and increases the concentrations of elements beyond their naturally occurring amounts (i.e., enriched). This study was built upon previous community science work in which plant leaves were observed to collect similar concentrations to an accepted dust collection method and illustrated promise for their use as low-cost air quality monitors in these communities. This work investigated the concentration of Na, Mg, Al, K, Ca, Mn, Co, Cu, Zn, Mo, and Ba in dust from the leaves of community-collected backyard and garden plants (foliar dust), as well as if certain variables affected collection efficacy. This assessment evaluated (1) foliar concentration versus surface area for 11 elements, (2) enrichment factor (EF) values and ratios, (3) comparisons of foliar, garden, and yard samples to US Geological Survey data, and (4) what variable significantly affected dust collection efficacy. The EF results indicate that many of the samples were enriched (anthropogenically contaminated) and that the foliar samples were generally more contaminated than the yard and garden soil samples. Leaf surface area was the most influential factor for leaf collection efficiency (
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< 0.05) compared to plant family or sampling location. Further studies are needed that standardize the plant species and age and include multiple replicates of the same plant species across partnering communities. This study has demonstrated that foliar dust is enriched in the participating partnering communities and that plant leaf samples can serve as backyard aerosol pollution monitors. Therefore, foliar dust is a viable indicator of outdoor settled dust and aerosol contamination and this is an adoptable monitoring technique for “fenceline communities.”
Recent studies in the southwestern United States have shown that smelting processes and mine tailings emit heavy metal(loid)s that are distributed via wind dispersion to nearby communities. With ...increased attention regarding the effect of air pollution on environmental health, communities have begun to use citizen/community-based monitoring techniques to measure the concentration of metal(loid)s and evaluate their air quality. This study was conducted in a mining community to assess the efficacy of foliar surfaces as compared to an inverted disc (frisbee) to sample aerosol pollutants in ambient air. The assessment was conducted by evaluating As, Pb, Cd, Cu, Al, Ni, and Zn concentrations versus distance from a former smelter, statistical and regression analyses, and enrichment factor calculations compared to similar sites worldwide. Both the foliar and frisbee collection methods had a decrease in metal(loid)s concentration as a function of distance from the retired smelter. Statistical calculations show that the collection methods had similar mean concentrations for all of the metal(loid)s of interest; however, the tests also indicate that the frisbee collection method generally collected more dust than the foliar method. The enrichment factors from both collection methods were comparable to similar studies by other mining areas referenced, except for aluminum. Since there is evidence of enrichment, correlation between methods, and citizen/community science potential, these efforts show promise for the field. Further studies should consider alternating the types of plant used for foliar collection as well as collecting samples on a more frequent basis in order to sufficiently categorize results based on meteorological conditions.
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•Local observations/historical knowledge informed co-created citizen science program.•Sampling dust/aerosol pollutants in ambient air; foliar surface vs. inverted disc•Foliar surface collected similar metal(loid) concentrations as an inverted disc.•Inverted disc generally collected more dust than the foliar method.•Anthropogenic enrichment, correlation between methods indicates foliar is promising.
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