The present study aimed to assess the effects of anthropogenic activities on the heavy metal levels in the Langat River by transplantation of Corbicula javanica. In addition, potential ecological risk indexes (PERI) of heavy metals in the surface sediments of the river were also investigated. The correlation analysis revealed that eight metals (As, Co, Cr, Fe, Mn, Ni, Pb and Zn) in total soft tissue (TST) while five metals (As, Cd, Cr, Fe and Mn) in shell have positively and significantly correlation with respective metal concentration in sediment, indicating the clams is a good biomonitor of the metal levels. Based on clustering patterns, the discharge of dam impoundment, agricultural activities and urban domestic waste were identified as three major contributors of the metals in Pangsun, Semenyih and Dusun Tua, and Kajang, respectively. Various geochemical indexes for a single metal pollutant (geoaccumulation index (I gₑₒ), enrichment factors (EF), contamination factor (C f) and ecological risk (Er)) all agreed that Cd, Co, Cr, Cu, Fe, Mn, Ni and Zn are not likely to cause adverse effect to the river ecosystem, but As and Pb could pose a potential ecological risk to the river ecosystem. All indexes (degree of contamination (C d), combined pollution index (CPI) and PERI) showed that overall metal concentrations in the tropical river are still within safe limit. River metal pollution was investigated. Anthropogenic activities were contributors of the metal pollution. Geochemical indexes showed that metals are within the safe limit.

Pesticide risk assessment in the European regulatory framework is mandatory performed for active substances (pesticides) and the plant protection products they are constituents of. The aim is to guarantee that safe use can be achieved for the intended use of the product. This paper provides a feedback on the regulatory environmental risk assessment performed for pesticide registration at the EU and member state levels. The different steps of pesticide registration are addressed considering both exposure and hazard. In this paper, we focus on the environmental fate and behaviour in surface water together with the aquatic ecotoxicity of the substances to illustrate pesticide regulatory risk assessment performed for aquatic organisms. Current methodologies are presented along with highlights on potential improvements. For instance, as regards exposure aspects, moving from field based to landscape risk assessments is promising. Regarding ecotoxicology, ecological models may be valuable tools when applied to chemical risk assessment. In addition, interest and further developments to better take into account mitigation measures in risk assessment and management are also presented.

The eutrophication of Lake Taihu is the joint result of internal and external pollution. Research on the sources and flux loads of total nitrogen (TN) and total phosphorus (TP) has great significance for the control and management of the eutrophication issues facing Lake Taihu. We used hydrologic and water quality surveys of the surrounding rivers, precipitation investigations, and an experimental simulation of suspended sediment to analyze the sources of TN and TP to Lake Taihu and to estimate the flux loads of TN and TP. Our results indicate that (1) surrounding rivers, atmospheric deposition, and sediment suspension were the three main sources of TN and TP, with annual flux loads of 29.6 thousand t and 2.8 thousand t, respectively; (2) for the flux load of TN, influxes from surrounding rivers accounted for 61.1%, while atmospheric deposition contributed 23.5%, with both of these sources varying seasonally. Total nitrogen released from sediments contributed 15.4% of the TN load of Lake Taihu; (3) for TP flux load, surrounding rivers accounted for 42.8% and also showed seasonal variation. Atmospheric deposition and sediment release accounted for 17.9 and 39.3% with no significant seasonal variation. This article quantitatively analyzed the sources and loads of TN and TP and provided a basis for pollution control in Lake Taihu.

A survey of maize fields was conducted in northeast Italy from 1986 to 2014, resulting in a dataset of 1296 records including information on wireworm damage to maize, plant-attacking species, agronomic characteristics, landscape and climate. Three wireworm species, Agriotes brevis Candeze, A. sordidus Illiger and A. ustulatus Schäller, were identified as the dominant pest species in maize fields. Over the 29-year period surveyed, no yield reduction was observed when wireworm plant damage was below 15 % of the stand. A preliminary univariate analysis of risk assessment was applied to identify the main factors influencing the occurrence of damage. A multifactorial model was then applied by using the significant factors identified. This model allowed the research to highlight the strongest factors and to analyse how the main factors together influenced damage risk. The strongest factors were: A. brevis as prevalent damaging species, soil organic matter content >5 %, rotation including meadows and/or double crops, A. sordidus as prevalent damaging species, and surrounding landscape mainly meadows, uncultivated grass and double crops. The multifactorial model also showed how the simultaneous occurrence of two or more of the aforementioned risk factors can conspicuously increase the risk of wireworm damage to maize crops, while the probability of damage to a field with no-risk factors is always low (<1 %). These results make it possible to draw risk maps to identify low-risk and high-risk areas, a first step in implementing bespoke IPM procedures in an attempt to reduce the impact of soil insecticides significantly.

A feasible and efficient type of biological sludge-activated carbon (BSAC) was produced by co-pyrolysis of municipal sewage sludge (MSS) and walnut shell (4:1, w/w) at 500 °C. It was found that BSAC was typical mesoporous material with favorable pore structure and abundant surface functional groups, whose performance was improved compared with conventional sludge-activated carbon (CSAC), combined with walnut shell-activated carbon (WSAC). The migration and transformation behavior of heavy metals (Zn, Cu, Ni, Cd, and Cr) in raw material after co-pyrolysis process were investigated. The results indicated that co-pyrolysis could promote mobile fraction (acid soluble/exchangeable and reducible fractions) of heavy metals to stable fraction (oxidizable and residual fractions). The leaching concentrations Cu, Ni, Cd, Cr, and Zn were lower than restrictive standards in China, and the environmental risk assessment results showed that after co-pyrolysis, the risk levels of Cu, Ni, and Cd were decreased to low risk, especially Cr in product was confirmed to no risk.

Ultrastructure alterations in spermiogenesis of the ground beetle, Blaps sulcata (Coleoptera: Tenebrionidae) were studied in normal adult males and in two male groups irradiated by gamma rays of 3 and 16 μSv/h dose rate. Ultrastructure examination of irradiated sperms revealed many alterations both in the head and in the flagellum regions of mature sperm. Alterations of the head region included nuclei with uncondensed chromatin materials and irregular nuclear envelope. Abnormal flagella contained malformed mitochondrial derivatives and damaged axonemes in addition to the absence of accessory bodies. Bi- and multi-flagellate sperms (with two, three, and four axonemes) were the most common alterations. Sperm cells with residual bodies were also obtained. Agglutinated sperms and sperms with enlarged and/or vacuolated cytoplasm were common. Sperm abnormalities were more pronounced in males irradiated by 16 μSv/h dose rate than those irradiated by 3 μSv/h. Spermiogenesis alterations induced by irradiation of B. sulcata may be used as a monitoring model for predicting the effects of environmental radioactivity.

Human populations are using oceans as their household dustbins, and microplastic is one of the components which are not only polluting shorelines but also freshwater bodies globally. Microplastics are generally referred to particles with a size lower than 5 mm. These microplastics are tiny plastic granules and used as scrubbers in cosmetics, hand cleansers, air-blasting. These contaminants are omnipresent within almost all marine environments at present. The durability of plastics makes it highly resistant to degradation and through indiscriminate disposal they enter in the aquatic environment. Today, it is an issue of increasing scientific concern because these microparticles due to their small size are easily accessible to a wide range of aquatic organisms and ultimately transferred along food web. The chronic biological effects in marine organisms results due to accumulation of microplastics in their cells and tissues. The potential hazardous effects on humans by alternate ingestion of microparticles can cause alteration in chromosomes which lead to infertility, obesity, and cancer. Because of the recent threat of microplastics to marine biota as well as on human health, it is important to control excessive use of plastic additives and to introduce certain legislations and policies to regulate the sources of plastic litter. By setup various plastic recycling process or promoting plastic awareness programmes through different social and information media, we will be able to clean our sea dustbin in future.

Polybrominated diphenyl ethers (PBDEs) have been extensively used as flame retardants in consumer products. PBDEs rapidly bioaccumulate in the environment, food, wild animals and humans. In this review, we investigated the harmful effects of PBDEs on humans, especially in early life, and summarised the levels of PBDEs in human biological samples (breast milk, cord blood and placentas). In addition, we described the spatiotemporal distribution of PBDEs in this review. PBDE levels in breast milk, cord blood and placentas were generally higher in North America than in other regions, such as Asia, Europe, Oceania and Africa. However, high levels of PBDEs in human biological samples were detected at e-waste recycling sites in South China, East China and South Korea. This finding suggests that newborns living in e-waste regions are exposed to high levels of PBDEs during prenatal and postnatal periods. The time trends of PBDE concentration differed according to the region. Few studies have investigated PBDE levels in humans from 1967 to 2000, but they increased rapidly after 2000. PBDE concentration peaked at approximately 2006 globally. Compared with other PBDE congeners, BDE-47, BDE-153 and BDE-209 were the major components, but the detection rate of BDE-209 was lower than those of others. Future studies should focus on determining the BDE-209 concentration, which requires the implementation of different analytical approaches. Additionally, the levels of PBDEs in human samples and the environment should be monitored, especially in e-waste recycling regions. Graphical abstract The figures described the spatial distribution of the lowest (Fig. a1) and highest concentration of ∑PBDE (Fig. a2) in different countries by 2006 and described the spatial distribution of the lowest (Fig. b1) and highest concentration of ∑PBDE (Fig. b2) in different countries from 2007 to 2015. All the figures indicated that the levels of PBDEs in North America were substantially higher than those in many regions of Europe, Asia, Oceania, or Africa. Comparing Fig. a1–b1 or Fig. a2–b2, increasing trends were observed in some countries, especially in some regions in China, Korea and Canada.

Liberia is endowed with an impressive stock of mineral reserves and has traditionally relied on mining, namely iron ore, gold, and diamonds, as a major source of income. The recent growth in the mining sector has the potential to contribute significantly to employment, income generation, and infrastructure development. However, the development of these mineral resources has significant environmental impacts that often go unnoticed. This paper presents an overview of the Liberian mining sector from historical, current development, and economic perspectives. The efforts made by government to address issues of environmental management and sustainable development expressed in national and international frameworks, as well as some of the environmental challenges in the mining sector are analyzed. A case study was conducted on one of the iron ore mines (China Union Bong Mines Investment) to analyze the effects of the water quality on the local water environment. The results show that the analyzed water sample concentrations were all above the WHO and Liberia water standard Class I guidelines for drinking water. Finally the paper examines the application of water footprint from a life cycle perspective in the Liberian mining sector and suggests some policy options for water resources management.