Mercury, in the form of monomethylmercury, can accumulate in fish to high concentrations, presenting the greatest concern for human exposure to this potent neurotoxin. New long-term research of fish in a natural setting has shown that removal rates of the toxin from body tissues are likely to be even slower than thought.

A new study assessing the levels, and potential health risk, of toxic heavy metals in market-bought fish and shellfish in Spain has found that they are generally below European Commission regulatory limits, and that these products are therefore safe to eat for the average consumer in Spain. However, for high level consumers of specific fish species, toxic element levels could pose a risk to health.

Exposure to polluted soil can affect human health, but the risk may vary depending on the soil type. A recent study has shown that the differing amounts of cadmium and lead that can be dissolved in the human digestive system can be predicted for contaminated agricultural, urban and woody habitat soils using a model. Its authors suggest this is a useful method for assessing the risks of contaminated land.

Recent research has found that silver nanoparticles in sewage sludge, which is used on agricultural land as a fertiliser, can be toxic to soil microorganisms. The researchers calculated that a maximum of 30mg of silver nanoparticles per kilogram of sludge can be applied to land before harm occurs, based on typical application rates in Germany of five tons per hectare of farmland every three years.

Leakage of radioactive material from the wreck of the nuclear submarine K-159 in the Barents Sea could increase levels of radioactivity in local populations of cod by a hundred times, new research suggests. However, this level remains well below ‘safe’ standards set by the Norwegian government.

Calculating the costs of nitrous oxide (N2O) emissions to society as well as business is vital to understand the true economic gains of reducing N2O emissions, new research suggests. Increasing nitrogen use efficiency by 20% by 2020 could bring global annual benefits to the climate, health and environment worth US $160 (€118) billion, the researchers conclude.

A technique that can detect the array of pesticides bees might be exposed to has been developed in Poland. The simplicity, speed and small sample sizes required for screening makes this technique an improvement over other methods, say the researchers behind its development.

Use of the rodenticide bromadiolone to control water voles in France may also result in population declines of the near-threatened red kite, a new study suggests. The researchers propose a range of alternative forms of controlling vole populations, limiting the need for environmentally-damaging poisons.

The health impacts of consuming food that has been grown using cadmium-contaminated fertilisers are an increasing concern. New Danish research has estimated that the annual monetary cost of these impacts is €15.53 per km2 of agricultural land treated with mineral fertilisers. This cost rises to €37.04 per km2 if pig manure is used.

Farmers could help to maintain populations of bees and other pollinators by sowing inexpensive seed mixes on their land, a new study suggests. Researchers surveyed pollinators visiting study plots in Berkshire, UK, and explored how sowing different seed mixes and using different management techniques affected the flowers produced and the pollinators visiting them.

Thousands of tonnes of chemical warfare agents were dumped into the Baltic Sea after the Second World War. A recent study has shown that fish caught near the dumping grounds show high levels of genetic and cell damage, revealing the long legacy of these toxic substances.

The Deepwater Horizon oil spill is likely to have damaged large numbers of tuna and amberjack fish embryos, new research suggests. Fish embryos exposed to oil samples taken during the spill developed abnormalities in their hearts and, consequently, their spines, fins and eyes. This is likely to have caused population declines in these commercially important species, the researchers conclude.

Polycyclic aromatic hydrocarbon (PAH) contamination in catfish in Italian rivers has been found to exceed EC limits, a new study has found. Benz[a]pyrene, which can potentially cause cancer, was found in all samples and in 9% exceeded limits set in EU food safety legislation. Heavy road traffic and inadequately treated wastewater are the most likely cause of these high levels of PAH pollution, say the researchers.

Levels of aquaculture pesticides exceed UK environmental quality standards (EQSs) in samples taken from near Norwegian fish farms, a recent study has shown. The researchers examined five pesticides used to kill sea lice (Lepeophtheirus salmonis) and showed that in many cases their concentrations exceeded UK EQSs. They used UK standards, they explain, because there are currently no Norwegian EQSs for these chemicals, and call for international quality standards to be drawn up.

Silver nanoparticles are toxic to common bacteria at concentrations found in many aquatic environments across the globe, new research has found. Bacteria often form a key part of ecosystems and these impacts may be felt by the entire system, the researchers warn.

Mercury contamination of some wild fish species in areas of the Czech Republic may put anglers’ health at risk, a new study suggests. The research showed that EU-wide and Czech national regulatory limits for mercury were exceeded in at least one analysed sample at 63% of the sites surveyed. However, contamination levels varied substantially between locations and species, the researchers say.

Rodents poisoned by pest control substances may pose a threat to protected birds if the carcasses are not removed quickly enough. A new study found that dead water voles on farmland were scavenged rapidly by red kites and buzzards, suggesting that regular removal is needed to reduce poisoning risks.

Nutrient pollution in The Netherlands is falling as a result of national and EU policies, new research has shown. However, many waters still routinely fail to meet environmental quality standards. The study, which focused on the headwaters of 167 rivers where agricultural fertilisers are the main cause of pollution, showed that up to 76% of these did not meet water quality standards.

Neonicotinoid and fipronil insecticides have a range of impacts on birds, mammals and fish, a new review of scientific literature has found. A house sparrow would need to eat just one and a half beet seeds treated with a common neonicotinoid to receive a lethal dose, for instance. The insecticides may also have equally important effects on vertebrate wildlife, such as reducing insect prey and hence food supply.

The combined effects of pollution and rising levels of atmospheric greenhouse gases, including CO₂, may have effects on marine ecosystems that are more damaging than expected, warns new research. The study found that bacteria capable of breaking down oil pollution were far less abundant in sediment in acidified waters. Although increased ultraviolet-B (UV-B) light reduced these negative impacts, the researchers caution that deeper waters or other waters with less UV-B, may still suffer.

A guide has been published on the known and potential health and safety effects of human exposure to graphene. It is designed to help inform those working with graphene and graphene-based nanomaterials and could be especially useful as a growing number of industries begin to experiment with and use these materials.

A drug used to treat parasite infections at fish farms can contaminate the surrounding environment and threaten local wildlife, a new study shows. Following a week-long treatment at a Norwegian salmon farm, the authors found concentrations of an anti-sea-lice drug that were high enough to kill some crabs, shrimps and lobsters. However, they suggest the drug is not likely to pose a risk to humans.

Wastewater emptied from commercial fishing boats is an overlooked source of marine pollution, a new US study shows. The researchers suggest that this type of pollution should be given further consideration when assessing the overall environmental impact of fishing, as it may pose a risk to human health and marine life.

Beetles that are helpful to farmers can be poisoned if they feed on slugs that have eaten crops treated with neonicotinoids, a new study reports. The slugs themselves are not harmed by neonicotinoids. In American field trials, researchers found that plots planted with neonicotinoid-treated soybeans contained more slugs, fewer beetle predators and had 5% lower yields. The insecticide may be reducing the beetles’ effectiveness as a natural control of slug pests.

Fish fed polystyrene nanoparticles are less active and show changes to their brains and metabolism, according to a study by Swedish and Danish researchers. The findings suggest that nanoparticles in the environment could have a major impact on fish and aquatic ecosystems.

Disposable components of Electronic Nicotine Delivery Systems (ENDS), such as e-cigarettes and e-pens, could pose a potential environmental risk unless properly regulated, suggests new research. The study examined the levels of potentially toxic chemicals in disposable battery and 'cartomiser' ENDS components.

Natura 2000 sites may not be adequately protected in Eastern Europe, according to a recent publication. Researchers in the Czech Republic found that, despite being designated as a Natura 2000 site, environmentally damaging activities continued in the Šumava National Park. They recommend that good environmental education is needed to help post-communist countries implement Natura 2000 and better recognise its value and importance.

The risk of eutrophication as a result of nitrogen and phosphorus pollution in Europe’s freshwaters fell by 22% in lakes and by 38% in rivers between 1985 and 2011, new research has shown. The researchers analysed data across 88 European river basins using a new statistical approach which could be used to help identify factors which increase eutrophication risks.

The ability of organisms to adapt to toxic chemicals like pesticides is essential for their survival, but also an agricultural annoyance. This study shows that interactions between different species can delay the development of pesticide resistance and therefore suggests that biodiversity supports effective pest management.

The contamination of hazardous substances in estuaries can have negative effects on biodiversity. Using experimentally supported indicators, this study analysed the environmental risks posed by 22 different contaminants in UK estuaries and coastal waters, finding that substances banned over 20 years ago continue to persist in the marine environment.

Controls on pharmaceutical production in the EU should be changed to guard against the spread of antibiotic resistance, protect wildlife and improve transparency in the industry, a team of scientists from Sweden and the UK recommends. The scientists propose 10 changes to the environmental risk assessment (ERA) of pharmaceuticals.

Oil spills at sea can be catastrophic events, with oil and discharged toxins, including polycyclic aromatic hydrocarbons, threatening marine wildlife and coastlines, damaging healthy ecosystems and harming livelihoods. A recent study found that using dispersants moderately decreased the number of cod eggs and larvae affected by spills off the Norwegian coast.

Cyanobacteria — often referred to as blue-green algae — are found in water bodies around the world and can produce toxins with potential health risks. This US-wide study found a significant positive association between cyanobacterial bloom coverage and death by non-alcoholic liver disease. The researchers say their study suggests some evidence of a potential health risk and should be used to generate further investigation into the health impact of cyanobacteria.

Persistent organic pollutants (POPs) are priority pollutants that pose a risk to human health, and can be passed on to children via breast milk. This study investigated how concentrations of POPs in breast milk vary worldwide by reviewing studies published between 1995 and 2011. They found that levels of polychlorinated biphenyls (PCBs) and dioxins in breast milk are higher in Europe and North America, whereas pesticides are more prevalent in Africa and Asia. The authors call for harmonisation of methodologies to enable high quality comparisons between studies.

Halogenated nitrogenous disinfection by-products (N-DBPs) in water increase bacterial resistance to antibiotics, new research shows. The study found that a strain of bacteria which can cause disease in humans, Pseudomonas aeruginosa, increased its resistance to a range of different antibiotics by an average of 5.5 times after the bacteria were exposed to chemicals which form as by-products of common water treatment procedures. The results highlight the risks to public health which these currently unregulated by-products may cause.

A novel approach for identifying and isolating anthropogenic – including microplastic – particles in fish stomachs has been devised by researchers in Belgium. The new method may enable scientists and policymakers to better assess the presence, quantity and composition of particles ingested by marine life, and improve understanding of the environmental effects of marine plastic pollution.

Intersex fish, in which male reproductive tissues become ‘feminised’, are increasingly being identified. This effect has traditionally been attributed to birth-control medications. This study exposed fish to a widely prescribed anti-diabetic, metformin. Male fish developed female sexual characteristics and reproductive rate decreased, which suggests that metformin may be a non-traditional endocrine-disrupting compound.

Environmental risk assessment is challenging because of the complexity of the physical and ecological systems around us. Natural disasters, the spread of dangerous substances, ecosystem changes leading to food and health security issues, and the emergence of new materials, new events and new knowledge make it essential to update our understanding continually, to be able to identify threats and opportunities for timely action. This Thematic Issue presents some collaborative and integrated paths towards forward-thinking assessment and management of environmental risks.

New research has combined two different techniques for identifying hazards and assessing risks into a single dynamic risk assessment process. The new approach fills a gap in many current risk assessment techniques as it can be applied throughout the lifetime of a process, not just during its design phase, taking into account new information to update risk assessments and calculations systematically.

Chemical risk assessment and governance can be integrated and harmonised, but only up to a limit, albeit a variable limit, finds new research. The study’s authors examined the socio-political processes and factors surrounding integrated risk assessment and governance associated with chemicals in the EU. The research suggests there are opportunities for improvement if different views and implications of risk integration are considered through open communication and negotiations.

Chemicals regulation in Europe could be improved through integrated risk assessment, says an EU project. The project team presents a range of perspectives on how the integration of hazard, exposure and socio-economic assessments can be promoted and implemented.

Lithium production has increased dramatically during the past decade. A new study has found that exposure of rainbow trout to lithium results in fast accumulation in plasma and the brain, along with decreased concentrations of ions such as sodium.

The emissions of two perfluoroalkyl acids (PFAAs) into the Danube River Basin have been estimated in a test of four different hypotheses regarding the factors affecting those emissions. The results were used to simulate water concentrations for comparison with measured data. The researchers found that incorporating wastewater treatment information and wealth distribution alongside population data can improve the accuracy of emissions estimates.

A growing body of evidence suggests that endocrine-disrupting compounds (EDCs) are contributing to declines in fertility. This case-control study found that EDCs were associated with changes to sex hormones and risk of subfertility in men. The researchers say environmental levels of these chemicals should be reduced to protect male fertility.

To assess the risk posed by metals in the aquatic environment, Biotic Ligand Models (BLMs) were developed, and are now considered suitable for use in regulatory risk assessments. This study reviews the advantages of BLMs and BLM-based software tools, providing examples from across the EU, and offers recommendations for their widespread implementation.

Mercury-resistant bacteria could help scientists to understand more about mercury cycling in the environment. In a new study, researchers identified one particular strain of soil bacterium that could serve as a model for the conversion of the toxic metal into less toxic forms. They also discovered a new gene involved in the conversion process.

Researchers have recommended that fish from some sections of the River Po and the River Lambro, one of the Italian River Po tributaries, should not be eaten due to high levels of some endocrine-disrupting chemicals in the river sediments and fish. This recommendation is based on an extensive update regarding pollution levels of such substances in the rivers.

Bisphenol A (BPA) is a chemical that is widespread in the environment. Researchers reviewed and critically discussed the sources and routes of human exposure to chlorinated derivatives (ClxBPA) and alternatives to BPA (BPF, BPS), as well as their metabolism, toxicity and concentrations in human tissues. The researchers suggest BPA alternatives and derivatives may have similar effects, and provide directions for future research.

Widespread use of antibiotics has led to pollution of waterways, potentially creating resistance among freshwater bacterial communities. A new study looked for antibiotic resistance genes in a river basin in Spain, revealing that wastewater discharges can promote the spread of antibiotic resistance in streams and small rivers.

Growing sugar beet varieties which are resistant to their pest, the cyst nematode, is the best way to achieve high sugar yields in northern Germany, recent research has concluded. The researchers say this method is better than growing trap crops or using pesticides to control the pests.