In this short communication, we estimate that California's wildfire carbon dioxide equivalent (CO₂e) emissions from 2020 are approximately two times higher than California's total greenhouse gas (GHG) emission reductions since 2003. Without considering future vegetation regrowth, CO₂e emissions from the 2020 wildfires could be the second most important source in the state above either industry or electrical power generation. Regrowth may partly of fully occur over a long period, but due to exigencies of the climate crisis most of the regrowth will not occur quickly enough to avert greater than 1.5 degrees of warming. Global monetized damages caused by CO₂e from in 2020 wildfire emissions amount to some $7.1 billion USD. Our analysis suggests that significant societal benefits could accrue from larger investments in improved forest management and stricter controls on new development in fire-prone areas at the wildland-urban interface.

Problems with PM₂.₅ pollution in the Pearl River Delta (PRD) have been significantly reduced since the Chinese government released a series of emission control policies including the strengthened controls in the 13ᵗʰ Five-Year Plan. This study assessed the efficacy of emission control measures using the Community Multiscale Air Quality (CMAQ) model to provide data-driven support to government decision making, which is becoming increasingly important. This study aimed to quantitatively evaluate the integrated results of proposed policies for controlling PM₂.₅ concentrations. Accordingly, the regional 2015 emission inventory was modified with recently released government data for the PRD, and scenarios for four dynamical emission-reduction policies (S1–S4) were explored. The results show that all four proposed control measures can help to reduce PM₂.₅ concentrations throughout Hong Kong (HK), Macao, and the PRD economic zone (PRD EZ) by 2020. In all cases, reductions in PM₂.₅ concentrations were larger over PRD EZ than over HK. For HK, the predicted annual concentrations of PM₂.₅ were less than 20 μg/m³ for S1–S3 and less than 15 μg/m³ for S4. For Macao, the predicted annual concentrations of PM₂.₅ were less than 25 μg/m³ for S1 and less than 15 μg/m³ up to S3. Regionally, HK had the lowest PM₂.₅ levels, and the area around Foshan had the highest. Controlling the sources of air pollution (i.e., industry, transport, power production, and other sources) within PRD can get most of the PRD EZ region to below 35 μg/m³. Similar national air quality management efforts could reduce PM₂.₅ levels to less than 25 μg/m³ in the PRD EZ and less than 15 μg/m³ in HK. Control measures in S1 led to significant improvement in Shenzhen and HK, but the S3 option brought the greatest improvement for PRD EZ and Macao. The S4 policy option led to substantial reductions, particularly for HK.

Polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons (AHs), including petroleum biomarkers, were studied in four sediment cores collected around Deception and Penguin Islands, Antarctica. Total PAHs in Deception Island (DCP) samples ranged from 2.0 to 26.8 ng g⁻¹, and in Penguin Island (PGI) varied between 13.2 and 60.3 ng g⁻¹. Multiple sources of PAHs were verified in DCP, with petrogenic-derived compounds being predominant over the last 10 years. In PGI, PAHs related to natural contributions from the erosion of coal deposits were reported. Total AHs in DCP ranged from 4.5 to 19 μg g⁻¹ and in PGI varied between 5.3 and 21.9 μg g⁻¹. In DCP, the n-alkanes distribution pattern showed the presence of petroleum residues in the top sections and both terpanes and hopanes were detected, related to the use of fossil fuels for power generation and in different types of vessels. In PGI, the main source of n-alkanes was marine inputs and only terpanes were detected. The slight increase in hydrocarbon levels observed from 1980 onward in DCP was assumed to be due to the development of tourism in the region and to the scientific station activities. In PGI, anthropogenic-related hydrocarbons were detected in the recent sections and were linked to the development of tourism near the island, scientific activities and the increase in vessel traffic. In general, the concentrations of hydrocarbons found around both islands were comparable to those found in uncontaminated Antarctic regions.

In early nineteen century, a gas field was operational in southern part of Sindh, Pakistan for power production. The plant was completely un-operational for last three decades, whereas all wastage and raw materials are still dumped there, which might be the source to contaminate the ground water. The most of the workers population still living in different villages nearby the gas field. In present study, evaluated the undesirable effects of the toxic metals (lead and cadmium) via consuming groundwater for drinking and other domestic purpose especially in children of ≤5.0 years. For comparative purpose groundwater of nonindustrial area (nonexposed) was also analysed and their impact on age matched children was carried out. Biological samples (scalp hair and blood) were collected from children of exposed and nonexposed areas. The Cd and Pb in scalp hair and blood samples were carried out by graphite furnace atomic absorption spectrometry. Whereas, Cd and Pb in groundwater obtained from both areas were determined prior to applied preconcentration method as reported in our previous works. The Cd and Pb contents in the groundwater of villages of exposed area were found in the range of 5.18–10.9 and 19.9–69.5 μg/L, respectively. Whereas, the groundwater of nonexposed area contains Cd and Pb in the range of 1.79–3.78 and 5.07–24.3 μg/L, respectively. It was observed that the concentrations of Cd and Pb in scalp hair and blood samples of children belongs to exposed area have ≥2.0 fold higher than the resulted data attained for age matched control children, indicating as the exposure biomarkers of toxic metals. The children belong to exposed area have poor health, anemic and low body mass index (<13 kg/m2). A significant positive correlations among Cd and Pb concentrations in biological samples of exposed subjects and groundwater was observed (p < 0.01).

Given its wide distribution in the natural environment and global transport potential, mercury (Hg) is regarded as a ubiquitous pollutant. In this study, we carried out nation-wide sampling campaigns across China to investigate the distribution of Hg in agricultural soils. Concentrations of Hg in the soils collected in 2011 and 2016 ranged from 0.04 to 0.69 and 0.06–0.78 mg kg−1, respectively. Based on the data from 2016, the reserve of Hg in the surface arable soils (0–20 cm) in China was 4.1 × 104 metric tons and Chinese cultivated soils accounted for 63.4–364 metric tons of Hg released to the global atmosphere. The soil Hg concentrations were significantly higher than the reference background level, highlighting the impacts of anthropogenic activities. The vertical distribution pattern showed a clear enrichment at the surface and a decrease with depth of the soils. Comparison of calculated geo-accumulation indexes among individual provinces showed that Northwest China had higher levels of Hg contamination than other regions of China, likely due to long-term energy related combustions in the area. Soil Hg level showed strong positive correlations with organic matter contents of soil, as well as the mean annual precipitation and temperature of the sampling locations. The non-carcinogenic human health risks of soil Hg were below the threshold level, but the general risk to the ecosystem was considerable. The increases in Hg accumulation from 2011 to 2016 at provincial level were found to relate to coal combustion, power generation and per capita GDP. This examination of energy consumption and socioeconomic drivers for China's soil Hg reserve increase is critical for direct Hg control by guiding policy-making and targets of technology development in era of rapid economic growth.

We assessed the level of atmospheric contamination by S, N and metals before, during and after the installation of a new thermoelectric plant that provides power to an oil refinery in Cubatão, SE Brazil. We measured the foliar accumulation in Lolium multiflorum “Lema” with the aim of evaluating risks to the Atlantic Rainforest that grows in the region. Al, Co, Cr, Cu, K, N, Ni, S, V and Zn were appropriate markers of the new air contamination profile associated with the modern technology. With the exception of V, the leaf contents of these elements significantly increased between the pre-operation to post-operation phases (Al, Co, N, K, S), or only during the transition phase (Zn, Cu, Cr, Ni), and returned to the previous levels after the total shutdown of the old system. Therefore, the expected environmental gain was not achieved with the installation of the new technology.

As the consumption of electricity increases, air pollutants from power generation increase. In metropolitans such as Hong Kong and other Asian cities, the surge of electricity consumption has been phenomenal over the past decades. This paper presents a historical review about electricity consumption, population, and change in economic structure in Hong Kong. It is hypothesized that the growth of electricity consumption and change in gross domestic product can be modeled by 4-parameter logistic functions. The accuracy of the functions was assessed by Pearson's correlation coefficient, mean absolute percent error, and root mean squared percent error. The paper also applies the life cycle approach to determine carbon dioxide, methane, nitrous oxide, sulfur dioxide, and nitrogen oxide emissions for the electricity consumption of Hong Kong. Monte Carlo simulations were applied to determine the confidence intervals of pollutant emissions. The implications of importing more nuclear power are discussed.

A multiple-year inventory of atmospheric antimony (Sb) emissions from coal combustion in China for the period of 1980–2007 has been calculated for the first time. Specifically, the emission inventories of Sb from 30 provinces and 4 economic sectors (thermal power, industry, residential use, and others) are evaluated and analyzed in detail. It shows that the total Sb emissions released from coal combustion in China have increased from 133.19t in 1980 to 546.67t in 2007, at an annually average growth rate of 5.4%. The antimony emissions are largely emitted by industrial sector and thermal power generation sector, contributing 53.6% and 26.9% of the totals, respectively. At provincial level, the distribution of Sb emissions shows significant variation. Between 2005 and 2007, provinces always rank at the top five largest Sb emissions are: Guizhou, Hunan, Hebei, Shandong, and Anhui.

Since early 2020, the world has faced an unprecedented pandemic caused by the novel COVID-19 virus. In this study, we characterize the impact of the lockdown associated with the pandemic on air quality in six major cities across the state of Florida, namely: Jacksonville, Tallahassee, Gainesville, Orlando, Tampa, and Miami. Hourly measurements of PM₂.₅, ozone, NO₂, SO₂, and CO were provided by the US EPA at thirty sites operated by the Florida Department of Environmental Protection during mid-February to mid-April from 2015 through 2020. To analyze the effect of the pandemic, atmospheric pollutant concentrations in 2020 were compared to historic data at these cities during the same period from 2015 to 2019. Reductions in NO₂ and CO levels were observed across the state in most cities and were attributed to restrictions in mobility and the decrease in vehicle usage amid the lockdown. Likewise, decreases in O₃ concentrations were observed and were related to the prevailing NOₓ-limited regime during this time period. Changes in concentrations of SO₂ exhibited spatial variations, concentrations decreased in northern cities, however an increase was observed in central and southern cities, likely due to increased power generation at facilities primarily in the central and southern regions of the state. PM₂.₅ levels varied temporally during the study and were positively correlated with SO₂ concentrations during the lockdown. In March, reductions in PM₂.₅ levels were observed, however elevations in PM₂.₅ concentrations in April were attributed to long-range transport of pollutants rather than local emissions. This study provides further insight into the impacts of the COVID-19 pandemic on anthropogenic sources from vehicular emissions and power generation in Florida. This work has implications for policies and regulations of vehicular emissions as well as consequences on the use of sustainable energy sources in the state.

Lead (Pb) is a toxic element which is released as a result of anthropogenic activities, and Pb stable isotope ratios provide a means to distinguish sources and transport pathways in receiving environments. In this study, isotopes of bioaccumulated Pb (²⁰⁴Pb, ²⁰⁶Pb, ²⁰⁷Pb, ²⁰⁸Pb) were examined for diverse terrestrial and aquatic biota from three areas in western Canada: (a) otter, marten, gulls, terns, and wood frogs in the Alberta Oil Sands Region (AOSR), (b) fish, plankton, and gulls of Great Slave Lake (Yellowknife, Northwest Territories), and (c) wolverine from the Yukon. Aquatic and terrestrial biota from different habitats and a broad geographic area showed a remarkable similarity in their Pb isotope composition (grand mean ± 1 standard deviation: ²⁰⁶Pb/²⁰⁷Pb = 1.189 ± 0.007, ²⁰⁸Pb/²⁰⁷Pb = 2.435 ± 0.009, n = 116). Comparisons with Pb isotope ratios of local sources and environmental receptors showed that values in biota were most similar to those of atmospheric Pb, either measured in local aerosols influenced by industrial activities in the AOSR or in lichens (an aerosol proxy) near Yellowknife and in the Yukon. Biotic Pb isotope ratios were different from those of local geogenic Pb. Although the Pb isotope measurements could not unambiguously identify the specific anthropogenic sources of atmospheric Pb in biota, initial evidence points to the importance of fossil fuels currently used in transportation and power generation. Further research should characterize bioavailable chemical species of Pb in aerosols and important emission sources in western Canada.