Environmental Pollution最新文献

Biochar is widely used for the remediation of heavy metal-contaminated soils. However, pristine biochar generally has limited active functional groups and adsorption sites, thereby exhibiting low immobilization performance for heavy metals. In addition to carbon (C), silicon (Si) is another common macro-element present in rice husk biochar, but it often exists in the form of amorphous oxide and therefore contributes little to the adsorption performance for heavy metals. The transformation of amorphous Si oxide to dissolved silicate through a precipitation effect can significantly improve its heavy metal immobilization capability. Herein, the amorphous Si oxide in rice husk biochar was activated by sodium hydroxide and then the dissolved silicate was immobilized by calcium salt. The as-synthetized Si-activated biochar was used to remediate cadmium (Cd)-contaminated soils. The results indicated that Si-activated rice husk biochar could reduce Cd migration and environmental risks by the transformation from exchangeable Cd into carbonate-bound and residual Cd. With increasing Ca: Si molar ratio, the content of CaCl₂ and H₂O-extractable Cd exhibited a decreasing trend. Moreover, a higher addition amount of Si-activated biochar improved the Cd immobilization efficiency. The application of 1.0% Ca/Si molar ratio of 2: 2 Si-activated rice husk biochar decreased the CaCl₂-Cd and H₂O-Cd concentration by a maximum of 83.7% and 90.5% compared with pristine rice husk biochar, respectively. The present work proposes an approach for highly efficient remediation of Cd-polluted soils by biochar.

The global impact of anticoagulant rodenticides (ARs) on non-target species is well-recognized. Birds of prey, as apex predators, are highly vulnerable to AR exposure and are widely used as biomonitors for priority pollutants in Europe. This study investigates differential SGAR exposure in raptors from insular versus continental regions, hypothesizing greater exposure in insular areas due to ecological factors like reduced prey diversity, intensive rodenticide use, and resistant rodent populations. We analyzed the livers of 190 common kestrels (Falco tinnunculus) and 104 common buzzards (Buteo buteo) across the Iberian Peninsula and its archipelagos using LC-MS/MS to assess their role as AR sentinels and the differences between insular and continental areas. Results revealed a high prevalence (>80%) of second-generation anticoagulant rodenticides (SGARs), with brodifacoum and bromadiolone, being the most frequent. Multiple SGAR detections were also common (≈50%). A binomial logistic regression showed that species and region significantly influence the likelihood of SGAR exposure. Kestrels had a greater probability of exceeding 100 ng/g wet weight (ww) compared to buzzards. Raptors from insular territories were ten times more likely to have higher SGAR concentrations than those from continental areas. However, the legal restriction on SGAR bait concentrations that came into effect in 2018 did not significantly impact exposure levels. This study highlights the need for targeted conservation efforts to mitigate AR exposure risk in vulnerable island ecosystems.

Mediterranean forests dominated by Quercus species are of great ecological and economic value. The Quercus pollen season, peaking in April, varies in concentration due to geographical and climatic factors and has a remarkable allergenic potential. This study investigates Quercus trends in the Alentejo region of Portugal and examines the influence of meteorological parameters on DPC, PSD and SPIn, as well as the impact on allergic respiratory disease. The results show a progressive increase in Quercus Forest area from 1995 to 2018. Temperature and Precipitation are a key factor influencing pollen concentration, especially before peak of pollen season and prior to the pollen season. Particularly prior to the season, the precipitation of t-6 before influence, significantly, the pollen production. On the other hand, Global Srad and RH determine the beginning of the season. Using quartile-based categorization and multivariate statistical analysis, we identified years and scenarios within the IPCC projections where meteorological conditions influence may SPIn production. The study found a statistically significant correlation between high Quercus pollen concentrations in April and increased antihistamine sales. These findings are crucial for enhancing pollen forecast models and early warning systems.

Biodegradable microplastics (MPs) can form biofilms through interactions with various microorganisms in aquatic system and can be exposed to organisms. This study first investigated biodegradability of polylactic acid (PLA) MPs and the characterization of PLA MPs before/after biofouling (4 weeks) and their toxic effects on the freshwater invertebrate Daphnia magna. The biodegradability rate of PLA MPs was up to 50% over 28 days, suggesting that even biodegradable MPs do not easily decompose under environmental conditions. Furthermore, biofouling of MPs led to an increase in size and, in the process, induced an additional functional peak in the PLA MPs. The exposure of biofouled MPs did not lead to a reduction in survival, reproduction, or growth during chronic exposure, nor did it cause feeding inhibition in juvenile (<4 days old) D. magna. However, pristine MPs significantly reduced survival, reproduction, and growth at concentrations of 5.0 mg L^-1. Overall, pristine MPs caused inhibition of reproduction and growth and high mortality in D. magna, while the biofouling process did not induce these effects. Our findings highlight the complex interactions between MPs and biological components in aquatic environments, emphasizing the importance of considering biofouling dynamics when assessing the ecological impacts of biodegradable MPs.

Surface water samples were collected from 264 sites across 46 U.S national parks during the period of 2009-2019. The number of sites within each park ranged from 1 to 31 and the number of samples collected within each park ranged from 1 to 201. Samples were analyzed for up to 340 trace organic contaminants (TrOCs), including pharmaceuticals, personal care products, pesticides, and various contaminants indicative of anthropogenic influence (e.g., fragrances, surfactants, flame retardants). A total of 155 TrOCs was detected in at least one sample with concentrations ranging from the reporting level of 10 ng/L (multiple contaminants) to 11,900 ng/L (p-cresol). Except for bisphenol A, DEET, theobromine, and gabapentin, TrOCs were detected in <20% of samples. Despite the relatively low detection frequencies, when TrOCs were detected, concentrations were similar to those reported from other regional or national studies. We compared detected concentrations to bioactivity concentrations and water quality benchmarks, when available, to identify occurrences of elevated concentrations and to estimate the potential for biological effects to aquatic biota. Elevated concentrations of 27 TrOCs, mostly pesticides, were detected throughout the study. To gain insight regarding potential sources, we related watershed characteristics (e.g., land cover, presence of point sources) to the number of TrOCs detected at each site. We found that the presence of wastewater treatment plants and the proportion of the watershed classified as agricultural land were the most influential variables for describing the number of pharmaceuticals and the number of pesticides present, respectively. This study represents the largest-scale study characterizing the presence and magnitude of TrOCs in U.S. national park surface waters, to date. These data provide a baseline that can be used to inform future monitoring within the parks and to assess changes in water quality.