New in Asian Journal of Ecotoxicology Mechanistic Insight into Cytochrome P450‐catalyzed Activation of Tobacco‐specific N'‐Nitrosoanatabine and N'‐Nitrosoanabasine Tobacco‐specific nitrosamines N'‐nitrosoanatabine (NAT) and N'‐nitrosoanabasine (NAB) are abundantly present in all tobacco products, cigarette smoke (see Figure 1), and even atmospheric particulate matters. The toxification routes of NAT

The World Health Organization estimates that 4.2 million people die annually as a result of external air pollution (World Health Organization 2016) and that each year 3.4 million deaths are related to problems involving poor water quality and sanitation (World Health Organization 2020). However, there is no information available on the number of people who die as a result of exposure to or contact

Neonicotinoids are a widely used class of pesticides. Co‐exposure to neonicotinoids and other classes of pesticides can exert potentiating or synergistic effects, and these mixtures have been detected in human bodily fluids. The present review summarizes studies into the effects of neonicotinoid‐containing pesticide mixtures on humans and other nontarget organisms. Exposure to these mixtures has been

Saflufenacil when applied to a field is susceptible to transport, degradation, and transformation. We used a laboratory‐based approach to model the fate of saflufenacil in the environment, the results of which are compared directly with those observed in a field study where saflufenacil was applied to a crop of winter wheat at a standard rate of 63 g of active ingredient/hectare. The water solubility

The frequency of wildfire is expected to increase with time as a function of climate change. Recent studies in our laboratory have demonstrated that pyrogenic polycyclic aromatic hydrocarbons can cause greater‐than‐additive effects in Hyalella azteca in the presence of low concentrations of Cu. We hypothesized that freshwater animals inhabiting Cu‐contaminated sites, such as those in the vicinity of

Feminization of male fish and the role of endocrine‐active chemicals in this phenomenon has been an area of intense study for many years. Estrone (E1), a natural steroid, is found in aquatic environments sometimes at high concentrations relative to the estrogenic steroids 17β‐estradiol (E2) and 17α‐ethynylestradiol. However, E1 has been less thoroughly studied than E2 or 17α‐ethynylestradiol due in

The abalone industry has suffered immense economic losses due to the occurrence of harmful algal blooms (HABs). Among the methods for mitigating HABs, modified clay is considered the most promising strategy and has been successfully used for field applications in many countries, and its environmental effects have become a subject of global concern. The effects of modified clay on the survival, growth

Fish acute toxicity tests are conducted as part of regulatory hazard identification and risk‐assessment packages for industrial chemicals and plant protection products. The aim of these tests is to determine the concentration which would be lethal to 50% of the animals treated. These tests are therefore associated with suffering in the test animals, and Organisation for Economic Co‐operation and Development

Dennis NM, Karnjanapiboonwong A, Subbiah S, Rewerts JN, Field JA, McCarthy C, Salice CJ, Anderson TA. 2020. Chronic reproductive toxicity of perfluorooctane sulfonic acid and a simple mixture of perfluorooctane sulfonic acid and perfluorohexane sulfonic acid to Northern Bobwhite Quail (Colinus virginianus). Environ Tox Chem 39:1101–1111. https://doi.org/10.1002/etc.4703 The authors of the above‐noted

In surface waters, the illumination of photoactive engineered nanomaterials (ENMs) with ultraviolet (UV) light triggers the formation of reactive intermediates, consequently altering the ecotoxicological potential of co‐occurring organic micropollutants including pesticides due to catalytic degradation. Simultaneously, omnipresent natural organic matter (NOM) adsorbs onto ENM surfaces, altering the

The present study examined the occurrence and concentration of per‐ and polyfluoroalkyl substances (PFAS) measured in game ducks (13 compounds), water, sediment, and soils (33 compounds) in waterways in Victoria, Australia. The study aimed to identify potential ecological and human health risks from measured PFAS concentrations. Four species of duck and samples of water, sediment, and soil were collected

Carbon dioxide (CO2) has been approved by the US Environmental Protection Agency as a new aquatic pesticide to control invasive Asian carps and other aquatic nuisance species in the United States. However, limited CO2 toxicity data could make it challenging for resource managers to characterize the potential risk to nontarget species during CO2 applications. The present study quantified the toxicity

My daily routine consists of walks, reading, and hobbies. The walks and readings motivated me to write about a continuing global problem, municipal solid waste (MSW), especially plastic. In this Points of Reference, I discuss the harm caused by plastics in the oceans and what we might do about it.

Equilibrium passive sampling methods (EPSMs) allow quantification of freely dissolved contaminant concentrations (Cfree) in sediment porewater. Polydimethylsiloxane (PDMS) is a convenient sampling polymer that can be equilibrated in field (in situ) or laboratory (ex situ) sediments to determine Cfree, providing reliable compound‐specific PDMS–water partition coefficients (KPDMS‐water) are available

There is growing concern about possible effects of exploitation of the Alberta Oil Sands on the ambient environment, including possible effects on populations of fishes in the Athabasca River and farther downstream in Lake Athabasca and the Slave River. In the present study, concentrations of metals in dorsal muscle tissue of 5 fish species—goldeye, northern pike, walleye, whitefish, and burbot—from

Pharmaceutical contamination of the environment is recognized as a global problem although most work has focused on Europe and North America to date and there remains a dearth of information for developing countries, including those in Africa. To address this data gap the occurrence of thirty‐seven pharmaceuticals belonging to nineteen therapeutic classes was monitored in surface water and effluents

The absence of chronic toxicity data for tropical marine waters has limited our ability to derive appropriate water quality guideline values for metals in tropical regions. To aid environmental management, temperate data are usually extrapolated to other climatic (e.g. tropical) regions. However, differences in climate, water chemistry and endemic biota between temperate and tropical systems make such

Antarctic marine environments are at risk from petroleum fuel spills as shipping activities in the Southern Ocean increase. Knowledge of the sensitivity of Antarctic species to fuels under environmentally realistic exposure conditions is lacking. In this study, the toxicity of three fuels, Special Antarctic Blend diesel (SAB), marine gas oil (MGO) and intermediate fuel oil (IFO 180) to a common Antarctic

The Alberta Oil Sands Region (AOSR) in Canada is home to one of the largest oil bitumen deposits in the world. Being a top predator with a small home range and sensitive to disturbances, the North American river otter (Lontra canadensis) has been designated as a sentinel species for the potential impacts of the natural resource exploitation on freshwater ecosystems in the AOSR. With an increasing interest

Neonicotinoid pesticides harm nontarget insects, but their sublethal effects on butterflies are understudied. We exposed larvae of 3 butterfly species (Pieris rapae, Colias philodice, and Danaus plexippus) to low levels of the neonicotinoid imidacloprid in their host plants and followed individuals to adulthood. Imidacloprid altered adult body size, especially in female monarchs, but its effects varied

The US Environmental Protection Agency (USEPA) is reviewing the protectiveness of the national ambient water quality criteria (WQC) for nickel (Ni) and zinc (Zn) and compiling toxicity databases to update the WQC. An amphipod (Hyalella azteca) and a unionid mussel (Lampsilis siliquoidea) have shown high sensitivity to Ni and Zn in previous studies. However, there remained uncertainties regarding the

Substances of unknown or variable composition, complex reaction products, or biological materials (UVCBs) pose unique risk assessment challenges to regulators and to product registrants. These substances can contain many constituents, sometimes partially unknown and/or variable, depending on fluctuations in their source material and/or manufacturing process. International regulatory agencies have highlighted

Effects‐directed analysis (EDA) is used to identify the principal toxic components within a complex mixture using iterative steps of chemical fractionation guided by bioassay results. Bioassay selection can be limited in EDA because of the volume requirements for many standardized test methods, and therefore, a reduced‐volume acute toxicity test that also provides whole‐organism responses is beneficial

The comprehensive aquatic systems model (CASM), an aquatic food web–ecosystem model, was developed originally to explore relationships between food web structure and ecosystem function, and was then subsequently adapted to assess potential ecological risks posed by chemical contaminants. The present short communication presents the history of the CASM, describes the model structure, lists the outputs

Dufulin is a new type of chiral antiplant virus agent independently developed in China. The present study was conducted to determine the effects of different concentrations of rac‐dufulin and dufulin enantiomers (1, 5, and 10 mg/L) on oxidative stress in Tubifex after exposure for 3, 7, and 14 d. Results showed that rac‐dufulin and individual enantiomers had no significant effects on total protein

Many urban lakes in Mexico City, such as Lake Chapultepec, are infested with high densities of cyanobacteria, particularly Microcystis. We tested the effect of cyanotoxins from cyanobacterial crude extracts on the demographic variables of zooplankton. The rotifers Brachionus havanaensis and Brachionus calyciflorus, and the cladocerans Ceriodaphnia dubia and Moina macrocopa were used for the assays

The combined algae test (CAT) is a 96‐well plate‐based algal toxicity assay with the green algae Raphidocelis subcapitata that combines inhibition of 24h population growth rate with inhibition of photosynthesis detected after 2h and 24h with pulse‐amplitude modulated (PAM) fluorometry using a Maxi‐Imaging PAM. The CAT has been in use for more than a decade but had limitations due to incompatibilities

There are various differences in size, behaviour and life history traits of non‐Apis bee species compared to honey bees (Apis mellifera (Linnaeus, 1758)). Currently, the risk assessment for bees in the international and national process of authorizing plant protection products has been based on honey bee data as a surrogate organism for non‐Apis bees. To evaluate the feasibility of a semi‐field tunnel

In vitro metabolic stability assays using isolated hepatocytes (RT‐HEP) or hepatic S9 fractions (RT‐S9) of Oncorhynchus mykiss were introduced to provide biotransformation rate data for the assessment of chemical bioaccumulation in fish. The present study explored the suitability of the RT‐HEP and RT‐S9 assays for difficult test chemicals, and the in vitro‐based predictions were compared to in silico‐based

Chemicals emitted into the environment are typically present at low concentrations but may act together in mixtures. Concentration‐response curves of in vitro bioassays were often linear <30% effect and the predictions for concentration addition (CA) of similarly acting chemicals and for independent action (IA) of dissimilarly acting chemicals overlapped. We derived a joint CA/IA mixture model for

Determining the fate of nitroaromatic compounds (NACs) in the environment requires the use of predictive models for compounds and conditions for which experimental data are insufficient. Previous studies have developed linear free energy relationships (LFERs) that relate the thermodynamic energy of NAC reduction to its corresponding rate constant. Here we present a comprehensive LFER that incorporates

Per‐ and poly‐fluoroalkyl substances (PFAS) encompass a large, heterogenous group of chemicals of potential concern to human health and the environment. Based on information for a few relatively well understood PFAS such as perfluorooctane sulfonate and perfluorooctanoate, there is ample basis to suspect that at least a subset can be considered persistent, bioaccumulative, and/or toxic. However, data

Per‐ and polyfluoroalkyl substances (PFAS) often occur together as contamination in exposure media such as drinking water or food. The relative potency factor (RPF) methodology facilitates the risk assessment of mixture exposure. A database of liver endpoints was established for 16 PFAS, using data with the same species (rat), sex (male), and exposure route (oral) and comparable exposure duration (42–90 d)

Perfluoroalkyl substances (PFAS) are surface‐active agents used in diverse industrial and commercial applications. They contaminate both freshwater and marine ecosystems, are highly persistent, and accumulate through trophic transfer. Seabirds are exposed to environmental contaminants due to their high trophic position in food webs and relatively long lifespan. We measured levels of 10 perfluoroalkyl

We analyzed concentrations and trends of perfluoroalkyl substances (PFAS) in blood plasma samples of bald eagle (Haliaeetus leucocephalus) nestlings at 6 study areas in the upper Midwest of the United States, 2006 to 2015, and long‐term trends at 2 Lake Superior sites, 1995 to 2015. Nestling blood plasma concentrations of the sum of 15 PFAS analytes (∑PFAS) differed among study areas and were highest

Dioxin exposure during bird embryonic development disrupts immunity as well as mechanisms involved in energy metabolism, potentially affecting negatively acute‐phase responses to pathogens. Thus, we hypothesized that embryonic exposure to 2,3,7,8‐tetrachlorodibenzodioxin (TCDD) changes the metabolism and blood physiology of domestic chicks, affecting their physiological competence for responding to

Although the introduction of non‐native fish species has been shown to alter trophic ecology in aquatic ecosystems, there has been limited research on how invasive species alter methylmercury (MeHg) biomagnification in lacustrine food webs. We sampled surface water and biota from 8 lakes in Quebec, Canada, spanning a range of dissolved organic carbon (DOC) concentrations (2.9–8.4 mg/L); 4 lakes were

Evaluating sediment recontamination due to stormwater discharges is important when evaluating the long‐term effectiveness of sediment remedial efforts in reducing biological impacts. The bioaccumulation of the heavy metals, Zn, Ni, Cu, Cd, Hg and Pb, and the metalloid As in a clam Macoma nasuta was studied in surficial sediments before and after stormwater inputs from Paleta Creek, CA during wet seasons

Despite the widespread use of parabens as antimicrobial preservatives in personal care products (PCP) and foodstuffs, recent studies show that exposure to parabens could result in endocrine disruption. The urinary methylparaben (MP), ethylparaben (EP), propylparaben (PP), and butylparaben (BP) among 100 adolescents and their relationships with using 19 personal care and 18 food products were evaluated

Per‐ and polyfluoroalkyl substances (PFAS) in drinking water are of increasing concern in the U.S., as well as worldwide, due to their widespread detection in public water systems and private domestic wells, extreme environmental persistence and evidence for adverse human health effects from environmentally relevant exposures.

This study accessed the use of diffusive gradients in thin film (DGT) as a surrogate for estimating the bioavailability and bioaccumulation of copper (Cu) and zinc (Zn) in a freshwater mussel. DGTs coupled with mussels were deployed in a constructed wetland and water quality parameters were measured for a 4‐day period on three continuous occasions during the 12‐day trial in the summer and winter, respectively;

If you were to gather a group of ecotoxicologists in a room and ask each what the most significant chemical threat is to the environment, chances are you would find as many different contaminants as individuals. Perhaps a more difficult question would be which, if any, truly represents an existential environmental threat relative to macro‐scale problems, such as habitat loss, invasive species, disease

A linear free energy model is presented that predicts the second‐order rate constant for the abiotic reduction of nitroaromatic compounds (NACs). Previously presented models use the one‐electron reduction potential of the NAC reaction . If is not available, it has been proposed that be computed directly or estimated from the gas‐phase electron affinity (EA). The model proposed uses the Gibbs free energy

Wastewater‐treatment plants (WWTPs) are regarded as one of the main sources of antibiotics in the environment. In the present study, the concentrations of multiple antibiotics and their metabolites belonging to 5 antibiotic classes were determined in 3 major Finnish WWTPs. An online solid phase extraction–liquid chromatography–tandem mass spectrometry method was used for the extraction and analysis

Several studies have reported the presence of smithsonite (ZnCO3) in soils polluted by zinc mining. The present study aimed to determine upper critical threshold values of Zn phytotoxicity in a substrate spiked with ZnCO3 and to compare them with those obtained in field‐collected soils. We studied Zn toxicity to perennial ryegrass (Lolium perenne L.) grown in pots with unpolluted peat treated with

We examined the bioaccumulation of essential (Cu, Fe, Se, and Zn) and non‐essential (As and Hg) trace elements in two aquatic invertebrate species (adult snails and mayfly nymphs) with different feeding habits at the site of a coal ash spill. Differences in food web pathway, exposure concentrations, and biological processing affected bioaccumulation patterns in these species. Mayflies had higher body

Nanometric revolution is underway, promising technical innovations in a wide range of applications, leading to a potential boost in environmental discharges. Nanoparticle propensity to be transferred throughout trophic chains and to generate toxicity was mainly assessed in primary consumers while a lack of knowledge for higher trophic levels persists. This study focused on a predatory fish, the European