peer reviewed | In the global COVID-19 epidemic, humans are faced with a new challenge. The concept of quarantine as a preventive measure has changed human activities in all aspects of life. This challenge has led to changes in the environment as well. The air quality index is one of the immediate concrete parameters. In this study, the actual potential of quarantine effects on the air quality index and related variables in Tehran, the capital of Iran, is assessed, where, first, the data on the pollutant reference concentration for all measuring stations in Tehran, from February 19 to April 19, from 2017 to 2020, are monitored and evaluated. This study investigated the hourly concentrations of six particulate matters (PM), including PM2.5, PM10, and air contaminants such as nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and carbon monoxide (CO). Changes in pollution rate during the study period can be due to reduced urban traffic, small industrial activities, and dust mites of urban and industrial origins. Although pollution has declined in most regions during the COVID-19 quarantine period, the PM2.5 rate has not decreased significantly, which might be of natural origins such as dust. Next, the air quality index for the stations is calculated, and then, the interpolation is made by evaluating the root mean square (RMS) of different models. The local and global Moran index indicates that the changes and the air quality index in the study area are clustered and have a high spatial autocorrelation. The results indicate that although the bad air quality is reduced due to quarantine, major changes are needed in urban management to provide favorable conditions. Contaminants can play a role in transmitting COVID-19 as a carrier of the virus. It is suggested that due to the rise in COVID-19 and temperature in Iran, in future studies, the effect of increased temperature on COVID-19 can be assessed.

Studies have shown that socioeconomic and environmental factors have direct/indirect influences on TB. This research focuses on TB prevalence of Hong Kong in relation to its compact urban development comprising of high-rise and high-density residential dwellings caused by rapid population growth and limited land resources. It has been postulated that occupants living on higher levels of a building would benefit from better ventilation and direct sunlight and thus less likely to contract infectious respiratory diseases. On the contrary, those on lower floors amid the dense clusters of high-rises are more susceptible to TB infection because of poorer air quality from street-level pollution and lesser exposure to direct sunlight. However, there have not been published studies to support these claims. As TB continues to threaten public health in Hong Kong, this study seeks to understand the effects of housing development on TB occurrences in an urban setting.

Erhai Lake in the Yunnan-Guizhou Plateau, a typical subtropical deep lake, experienced long-time input of nutrients and pollutants, which provides beneficial conditions for evolution and spread of resistance genes. In this study, the profile of bacterial community, antibiotic and metal resistance genes in sediments of Erhai Lake were analyzed via high-thought sequencing of 16S rRNA and metagenomic DNA. Proteobacteria, Firmicutes, Nitrospirae, and Bacteroidetes were found to be the main composition of the bacterial community. Multidrug-, bacitracin-, macrolide-lincosamide-streptogramin (MLS)- and tetracycline resistance genes were the primary antibiotic resistance gene (ARG) types with high relative abundance, whereas Multi-metal-, and arsenic- resistance genes were the primary metal resistance gene (MRG) types. The effects of nitrogen and phosphorus on the abundance of ARGs and MRGs depended on the different types. Some specific ARG (fosmidomycin resistance genes) and MRG types (multi-metal resistance genes) also showed significant geographic distribution. Bacterial community was the main driver shaping the resistome. Nutrients also played an essential role in structuring the bacterial community and resistome in the sediments of Erhai Lake. This study sheds light on the distribution and fate of resistome under a high load of nitrogen and phosphorus in a deep lake.

The blowout of the Deepwater Horizon (DWH) drilling rig in 2010 released an unprecedented amount of oil at depth (1,500 m) into the Gulf of Mexico (GoM). Sedimentary geochemical data from an extensive area (∼194,000 km2) was used to characterize the amount, chemical signature, distribution, and extent of the DWH oil deposited on the seafloor in 2010–2011 from coastal to deep-sea areas in the GoM. The analysis of numerous hydrocarbon compounds (N = 158) and sediment cores (N = 2,613) suggests that, 1.9 ± 0.9 × 104 metric tons of hydrocarbons (>C9 saturated and aromatic fractions) were deposited in 56% of the studied area, containing 21± 10% (up to 47%) of the total amount of oil discharged and not recovered from the DWH spill. Examination of the spatial trends and chemical diagnostic ratios indicate large deposition of weathered DWH oil in coastal and deep-sea areas and negligible deposition on the continental shelf (behaving as a transition zone in the northern GoM). The large-scale analysis of deposited hydrocarbons following the DWH spill helps understanding the possible long-term fate of the released oil in 2010, including sedimentary transformation processes, redistribution of deposited hydrocarbons, and persistence in the environment as recycled petrocarbon.

Perfluoroalkyl acids (PFAAs) are emerging contaminants that have raised great concern in recent years. While PFAAs manufacturing becomes regulated in developed countries, production has been partly shifted to China. Eight fluoropolymer manufacturing facilities located in the South Bohai coastal region, one of the most populated areas of China, have been used to manufacture PFAA-related substances since 2001. The environmental consequence of the intensive production of PFAAs in this region remains largely unknown. We analyzed 17 PFAAs in twelve coastal rivers of this region, and found staggeringly high concentrations of perfluorooctanoic acid (PFOA) ranging from 0.96 to 4534.41 ng/L. The highest concentration was observed in the Xiaoqing River which received effluents from certain fluoropolymer facilities. Principal component analysis indicated similar sources of several perfluoroalkyl carboxylic acids (PFCAs) in all rivers, which indicated that atmospheric transport, wastewater treatment and surface runoff also acted as important supplements to direct discharge to surface water.

Ecotoxicological bioassays, e.g. based on Danio rerio teratogenicity (DarT) or the acute luminescence inhibition with Vibrio fischeri, could potentially lead to significant benefits for detecting on site contaminations on qualitative or semi-quantitative bases. The aim was to use the observed effects of two ecotoxicological assays for estimating the extent of a Benzene groundwater contamination plume. We used a Maximum Entropy (MaxEnt) method to rebuild a bivariate probability table that links the observed toxicity from the bioassays with Benzene concentrations. Compared with direct mapping of the contamination plume as obtained from groundwater samples, the MaxEnt concentration map exhibits on average slightly higher concentrations though the global pattern is close to it. This suggest MaxEnt is a valuable method to build a relationship between quantitative data, e.g. contaminant concentrations, and more qualitative or indirect measurements, in a spatial mapping framework, which is especially useful when clear quantitative relation is not at hand.

Populations of some species of bats are declining in some regions of Europe. These declines are probably due to a range of pressures, including climate change, urbanization and exposure to toxins such as metals. This paper describes the development, paramaterisation and application of a spatially explicit modeling framework to predict the risks of soil-associated metals (lead, copper, zinc and cadmium) to bat health. Around 5.9% of areas where bats reside were predicted to have lead levels that pose a risk to bat health. For copper, this value was 2.8%, for cadmium it was 0.6% and for zinc 0.5%. Further work is therefore warranted to explore the impacts of soil-associated metals on bat populations in the UK.

Atmospheric dry deposition samples were collected in urban and suburban areas of Beijing during a coal-burning period. Chemical characteristics of lanthanoid elements (La–Lu) and five heavy metals (Cr, Co, Mo, Cd, and Pb) were analyzed to determine the variation in spatial scale and deposition provenances. Factor analysis and ternary diagrams were used to identify principle pollution sources. The LaCeSm ternary diagram was used to identify oil refineries using fluid catalytic converters and steel plants, but could not differentiate crustal materials. Lanthanoid characteristic parameters showed similarity between deposition and soil in the local and southwest area in the vicinity of Beijing. Analysis of the five heavy metals enabled discrimination of contaminants originating from human activities. Cd, Pb, and Mo were found to originate from vehicular traffic, whereas Co and Cr originated from industrial emissions and coal combustion. Discriminant analysis established the causes of spatial variation. The result shows that Co, Mo, and Pb can mark the differences between urban and suburban sites. From the PbMoCo plot, it was inferred that the different chemical characters are mainly due to the differing origins of depositions. Deposition samples in suburban areas are principally influenced by soil, chimney soot, and fertilizer, whereas those in urban area are mainly affected by traffic emissions.

Ship-generated oil pollution is a significant threat to the Mediterranean Sea. We present a geostatistical analysis of oil spills using three databases for the Mediterranean Sea: REMPEC (1977–2000) with 385 spills (17/year), ITOPF (1970–2018) with 167 spills (3.5/year) and EMSA (2015–2017) with 2066 detections (688/year). It was found that 88% of spills reported by REMPEC occurred near coastline areas, while 65% of the spills detected by EMSA occurred within a range of 22–100 km from the coastline. At the Exclusive Economic Zone (EEZ) level, EMSA oil spills densities were positively correlated with shipping and port activity. We conclude that there is a need to develop an open-access database of oil spills that will be based on both reports and remote sensing acquisition methods. Such a database will facilitate more efficient enforcement of international conventions in offshore areas and will increase the likelihood of effective response.

Manizales is a city in Colombia that presents high rates of thyroid cancer. It has a medium industrial development and there are concerns of the impact of their emissions on health, particularly on thyroid cancer. In this paper we characterize the geographical pattern of industrial atmospheric emissions of suspected thyroid carcinogens.We systematized data of industries in two groups. First, those with reports of atmospheric emissions of suspected thyroid carcinogens (reporting facilities – RFs), and then, industries not required to report or facilities with no-available emissions data but belonging to the same SIC-codes than RFs (nonreporting facilities – non-RFs). For non-RFs, annual average atmospheric emissions were estimated using a per-employee algorithm. The spatial pattern of sources emitting carcinogens was represented by plotting facilities by size and amounts of specific pollutants released.We found 11 RFs and 25 non-RFs in urban Manizales. RFs belong to the metalworking industries, plastics & rubber, manufacture of electrical and electronic devices, waste incineration, cremation, and meat production. Most of them were concentrated in the southeast of the city. Several RFs reported atmospheric emissions of carcinogens exceeding maximum permitted emission limits set in Colombian law. Most of non-RFs were micro and small industries, and were clustered in the southeast of the city and along the main road axis.We found clusters of pollution sources near densely populated areas. Thyroid cancer incidence might be greater in areas closer to industries than in furthest areas. We will submit a paper that studies this hypothesis soon.