Refining oil contaminants are complex and cause serious harm to the environment. Remediation of refining oil-contaminated soil is challenging but has significant impact in China. Two plant species Agropyron fragile (Roth) P. Candargy and Avena sativa L. and one bacterium Bacillus tequilensis ZJ01 were used to investigate their efficiency in remediating the refining oil-polluted soil sampled from an oil field in northern China. The simulated experiments of remediations by A. fragile or A. sativa alone and A. fragile or A. sativa combined with B. tequilensis ZJ01 for 39 days and by B. tequilensis ZJ01 alone for 7 days were performed in the laboratory, with B. tequilensis ZJ01 added before or after the germination of seeds. Seed germination rates and morphological characteristics of the plants, along with the varieties of oil hydrocarbons in the soil, were recorded to reflect the remediation efficiency. The results showed that the contamination was weakened in all experimental groups. A. sativa was more sensitive to the pollutants than A. fragile, and A. fragile was much more resistant to the oil hydrocarbons, especially to aromatic hydrocarbons. Adding B. tequilensis ZJ01 before the germination of seeds could restrain the plant growth while adding after the germination of A. fragile seeds notably improved the remediation efficiency. The degradation rate of oil hydrocarbons by B. tequilensis ZJ01 alone was also considerable. Together, our results suggest that the unitary remediation by B. tequilensis ZJ01 and the binary remediation by A. fragile combined with B. tequilensis ZJ01 added after the germination of seeds are recommended for future in situ remediations.

Balamtetik is the receiving body of the Rio Grande de Comitán and is located just at the outskirts of the Montebello National Park, Chiapas, México. Multi-elemental, infrared spectra, ¹³⁷Cs, ²¹⁰Pb, and diatom analyses in a 75-cm sediment core were used to reconstruct the recent disturbance history of the lake. The sequence chronology, based mostly on ¹³⁷Cs profiles, allowed to infer high sedimentation rates in Balamtetik (~ 7 mm/year) and a nearly cyclic series of disturbance events that can be related to anthropogenic causes such as deforestation and increased development of agriculture and urban areas at local and regional scale. These disturbance events show high local and regional erosion (high Ca, TIC, and Ti), soil organic matter (IR spectra), eutrophication (high P and diatoms), and anoxic bottom water conditions (low Mn) and can be dated to the early 1950s, the late 1950s, and from the 1980s until the 2000s. The entrance of wastewaters is related with an increase in salinity inferred by the diatom record and the organic matter type. The first two disturbance events are related to changes in land use during the agrarian reform that started during the 1940s; the last event is related with the increase in local population and the introduction of intensive agriculture. This last phase of disturbance corresponds with the reports of fish mortality events around 2003; however, high lake turbidity and anoxic bottom waters seem to have been established since the 1980s. The record from Lake Balamtetik also shows that during the intermediate periods, there was a recovery of the lake and its catchment; however, the future trends might be different, as the increase in the speed of organic matter and nutrients arrival to the lake reduces its resilience.

An air sampling study was conducted to evaluate personal formaldehyde exposures in a group of office workers spread across five geographical locations in the USA. Passive badge samples for formaldehyde were collected on three participants in each location, as well as in the office and home indoor microenvironments of each participant over 3 individual days. Median personal 24-h formaldehyde concentrations ranged from 9.9 to 18 μg/m³. Personal 24-h formaldehyde concentrations in one location were significantly higher than concentrations measured in the other four locations; no significant differences existed between any of the other locations. The participants in this study spent an average of 53% of their daily time in their homes, 36% at their office, and 11% in other indoor and outdoor locations. A comparison of measured 24-h personal formaldehyde concentrations and a model of average exposure based upon measured concentrations in the indoor microenvironments suggested that both the home and office formaldehyde concentrations were a strong predictor (R² = 0.88) of overall personal exposure. The data from this study are representative of office workers in urban environments and can be used as background formaldehyde exposure levels (in the absence of specific sources) for both occupational and nonoccupational exposure assessments.

A mine in an area of naturally occurring radioactive materials (NORM), characterized by acid mine drainage, generates effluents with natural radionuclide concentrations, usually above the limits authorized by the regulator. The plant exploiting NORM controls the water quality and discharges it into the aquatic environment after meeting technical requirements. Downstream, water usage is unrestricted. In order to reach activity concentrations in the released effluents below the authorized values, the facility applies a chemical treatment to the effluent. Then, to ensure the effectiveness of the treatment, the facility performs sampling of treated effluent and determines the activity concentration of natural radionuclides (Uₙₐₜ, ²²⁶Ra, and ²¹⁰Pb from the uranium series and ²³²Th and ²²⁸Ra from the thorium series). In the current study, the proportion and distribution of these radionuclides between the soluble and particulate fractions were determined. The measured activity concentrations were compared with the values proposed by the World Health Organization and Brazilian legislation, as well as other authorities, as regards the potable use from the radioprotection point of view. It was observed that the radionuclides are not in secular equilibrium. The fractions contribute differently to the total release of radionuclide, and there is no linear relationship between the fractions. The average activity concentrations did not result in radiological restrictions to water use, and the committed effective dose due to ingestion was estimated at 0.06 mSv y⁻¹. Therefore, there is no radiological restriction to water use, since the dose which was found was below the constraint value for the public.

Methamphetamine has become one of the most widely used illicit drugs in China. To understand the current situation in China, the prevalence and consumption of methamphetamine were estimated through wastewater-based epidemiology (WBE) in the present study. Methamphetamine concentrations ranged from 42.6 ng/L (Harbin) to 700 ng/L (Xi’an) in influent wastewater samples collected from 27 wastewater treatment plants (WWTPs) in 22 Chinese cities. The estimated consumption of methamphetamine was 23.0 (Dingxi) to 376 (Xi’an) mg/day/1000 inhabitants with a mean value of 157 mg/day/1000 inhabitants. The annual consumption in 2018 was estimated to be 84 tons (95% confidence interval, 44–136), which was 26% lower than that in 2014. The prevalence of methamphetamine use was 0.64% (95% confidence interval, 0.18–1.25), indicating that more than five million people used methamphetamine in 2018. Although drug abuse is common in the country, the consumption showed a different spatial pattern, with the highest values in Central China and the lowest use in Northeast China, so drug use is still considered a geographic and culture-dependent behaviour. The results indicated that WBE can not only be used to assess the trends of illicit drug use, but also to analyse the spatial differences in the whole country, which will provide complementary evidence for the prevention and control of methamphetamine use.

Treatment efficiency of iron-rich acid mine drainage (AMD; pH 3, and 2 and 4 g/L Fe) was tested in a laboratory tri-unit pilot-scale reactor (2.65 m³) for 1 year. The first unit consisted of a passive biochemical reactor (PBR1), filled with reactive mixture (50% of manure, sawdust, maple chips, compost, urea, sediment, and sand; 50% of calcite), with the aim to neutralize acidity and to partially remove metals. The second unit contained wood ash and acted as neutralizer and iron retention filter (by sorption and precipitation). The last unit was a second polishing PBR2, filled with reactive mixture (98% of manure, sawdust, maple chips, compost, urea, sediment, and sand; 2% of calcite), which aim was to remove the residual metals. The results showed that pH increased to about 6 and redox potential decreased significantly (from 550 mV to −100 mV). Iron, the most challenging metal in the AMD, decreased from 4 g/L (the highest tested concentration) to approximately 100 mg/L. The performance of the multistep treatment system was controlled by the capacity of the wood ash to immobilize iron.

Sandy dust storms in Iraq represented a serious problem for human health, not only in Iraq but also extended to be in other countries. Therefore, this study has assessed five heavy metals (Cd, Ni, Zn, Pb, and Fe) in the sandy dust storms from ten locations in the middle and south of Iraq. Contamination levels in the dust were evaluated by using various pollution indices. Heavy metals recorded a high pollution load index (PLI) that considered as baseline pollution in the dust. The geo-accumulation index (Igeo) values were moderately contaminated for Cd, and Pb, in case of potential ecology risk ([Formula: see text]), was a considerable risk for Cd. Based on multivariate analysis which is performed by principal component analysis (PCA), correlation analysis (r²) and cluster analysis (CA) revealed that heavy metals in sandy dust storms were possible from anthropogenic activities. The Cd, Ni, Zn, and Fe were from the same pollution sources, while Pb element was from the different pollution sources. Therefore, this data will be useful as sources to the Quality Control Department in Iraq to establish perfect qualitative standards and also to acquire a better quality of the atmosphere in Iraq and the region.

Cyanobacterial blooms pose a risk to wild and domestic animals as well as humans due to the toxins they may produce. Humans may be subjected to cyanobacterial toxins through many routes, e.g., by consuming contaminated drinking water, fish, and crop plants or through recreational activities. In earlier studies, cyanobacterial cells have been shown to accumulate on leafy plants after spray irrigation with cyanobacteria-containing water, and microcystin (MC) has been detected in the plant root system after irrigation with MC-containing water. This paper reports a series of experiments where lysis of cyanobacteria in abstracted lake water was induced by the use of hydrogen peroxide and the fate of released MCs was followed. The hydrogen peroxide–treated water was then used for spray irrigation of cultivated spinach and possible toxin accumulation in the plants was monitored. The water abstracted from Lake Köyliönjärvi, SW Finland, contained fairly low concentrations of intracellular MC prior to the hydrogen peroxide treatment (0.04 μg L⁻¹ in July to 2.4 μg L⁻¹ in September 2014). Hydrogen peroxide at sufficient doses was able to lyse cyanobacteria efficiently but released MCs were still present even after the application of the highest hydrogen peroxide dose of 20 mg L⁻¹. No traces of MC were detected in the spinach leaves. The viability of moving phytoplankton and zooplankton was also monitored after the application of hydrogen peroxide. Hydrogen peroxide at 10 mg L⁻¹ or higher had a detrimental effect on the moving phytoplankton and zooplankton.

Since the “5.12” Wenchuan earthquake in 2008, frequent geologic hazards along the Longmenshan fault zone have had significant impacts on the socioeconomic conditions in the earthquake-stricken areas. Therefore, from the perspective of earthquake-induced hazards, this paper focuses on analyzing the change rules of disaster resilience under the spatial and temporal aggregation effects of earthquake-induced hazards, and this analysis provides an important basis for understanding the developmental characteristics of earthquake-induced hazards and disaster prevention, and mitigation after earthquakes. This paper takes Wenchuan County as an example. By collecting the 2008–2018 landslide geological hazards data, the global autocorrelation coefficient and local autocorrelation coefficient are adopted to analyze the temporal trends and spatial patterns of earthquake-induced hazards. At the same time, from the socioeconomic perspective, two disaster resilience indexes, the compatibility coefficient of industrial and employment structure and per capita GDP growth rate, were constructed to analyze the disaster resilience under the spatial and temporal aggregation effect of landslide geological hazards. The results show that, on the temporal trend, the temporal aggregation effect of earthquake-induced hazards has periodically decayed with time; in the spatial distribution, the spatial clustering effect as a whole increases first and then decreases, and the scope of the aggregation effect tends to narrow spatially. Disaster resilience (Hₓy and RGDP) showed a trend of increasing first and then decreasing, and could not recover to the level before the earthquake in 2017, indicating that Wenchuan County was greatly affected by earthquake-induced hazards in the post-earthquake reconstruction process.

Pesticide chlorothalonil is widely applied in tea agroecosystem, potentially disturbing soil microbial-mediated nitrogen cycle. The underlying toxicity mechanism, however, is not well explored. Here, we investigated the long-term effects of chlorothalonil on soil microbial denitrification and N₂O emission pattern in a tea field after 40 days of exposure. Results showed that chlorothalonil inhibited denitrification process but remarkably promoted N₂O emission by 380–830%. Chlorothalonil significantly inhibited N₂O reductase activity but did not affected nosZ abundance. Our results further revealed that chlorothalonil influenced soil denitrification by directly suppressing microbial electron transport system activity, and decreasing electron donor nicotinamide adenine dinucleotide (NADH) and energy source adenosine triphosphate (ATP) levels. Additionally, chlorothalonil also downregulated denitrifying functional genes (narG, nirS, and norB) and declined the relative abundances of potential denitrifiers (i.e., Pseudomonas and Streptomyces). Stepwise regression and path modeling suggested that nitrate reductase was the most significant factor in explaining denitrification rate under chlorothalonil applications. This study provides important information for revealing the chronic impacts of pesticide on tea soil denitrification and N₂O emission on the basis of electron transport mechanism. Most significantly, N₂O emission is underestimated in chlorothalonil-treated soils, which suggests that future estimations of N₂O emission from agricultural lands should take account of pesticide dependency conditions.