Andrew C. Johnson

A national risk assessment for intersex in fish arising from steroid estrogens

The occurrence of intersex fish is widespread in the rivers of England and Wales. The extent of intersex in fish populations is believed to be strongly linked to their exposure to steroid estrogens. The present study presents, to our knowledge, the first national, catchment-based risk assessment for steroid estrogens in the world. A graphical information system-based model predicted the concentrations of estradiol (E2), estrone, and ethinylestradiol, which were combined and compared with known biological effect levels to predict the risk of endocrine disruption for 10,313 individual river reaches (21,452 km) receiving effluent from more than 2000 sewage treatment plants serving more than 29 million people. The large scale of this assessment underlines the usefulness of computer-based risk assessment methods. Overall, 61% [corrected] of the modeled reaches (all percentages are in terms of the total river length modeled) in England and Wales were predicted to be not at risk from endocrine disruption (mean concentrations, <1 ng/L E2 equivalents). A large range existed in the percentage of river reaches at risk in the various regions, from 5% in Wales to 67% in the Thames catchment. Important factors influencing this proportion are the population density, particularly their location, and the available dilution. A very small proportion of reaches (approximately 1-3%) were predicted to be at high risk (>10 ng/L E2 equivalents). Many of these high-risk reaches, however, were ditches, which were composed almost entirely of sewage effluent. The model could be applied equally well to any other chemical of concern emanating from the human population that would be impractical to assess by measurement.

The British river of the future: How climate change and human activity might affect two contrasting river ecosystems in England

The possible effects of changing climate on a southern and a north-eastern English river (the Thames and the Yorkshire Ouse, respectively) were examined in relation to water and ecological quality throughout the food web. The CLASSIC hydrological model, driven by output from the Hadley Centre climate model (HadCM3), based on IPCC low and high CO(2) emission scenarios for 2080 were used as the basis for the analysis. Compared to current conditions, the CLASSIC model predicted lower flows for both rivers, in all seasons except winter. Such an outcome would lead to longer residence times (by up to a month in the Thames), with nutrient, organic and biological contaminant concentrations elevated by 70-100% pro-rata, assuming sewage treatment effectiveness remains unchanged. Greater opportunities for phytoplankton growth will arise, and this may be significant in the Thames. Warmer winters and milder springs will favour riverine birds and increase the recruitment of many coarse fish species. However, warm, slow-flowing, shallower water would increase the incidence of fish diseases. These changing conditions would make southern UK rivers in general a less favourable habitat for some species of fish, such as the Atlantic salmon (Salmo salar). Accidental or deliberate, introductions of alien macrophytes and fish may change the range of species in the rivers. In some areas, it is possible that a concurrence of different pressures may give rise to the temporary loss of ecosystem services, such as providing acceptable quality water for humans and industry. An increasing demand for water in southern England due to an expanding population, a possibly reduced flow due to climate change, together with the Water Framework Directive obligation to maintain water quality, will put extreme pressure on river ecosystems, such as the Thames.

An assessment of the fate, behaviour and environmental risk associated with sunscreen TiO2 nanoparticles in UK field scenarios

The fate of Ti was examined in an activated sludge plant serving over 200,000 people. These studies revealed a decrease of 30 to 3.2 μg/L of Ti < 0.45 μm from influent to effluent and a calculated Ti presence of 305 mg/kg DW in wasted sludge. Thus, using sludge as a fertiliser would result in a predicted deposition of up to 250 mg/m² of Ti to soil surfaces using a recommended maximal agricultural application rate. Given the major use of TiO₂ in many industrial and domestic applications where loss to the sewer is possible, this measured Ti was presumed to have been largely TiO₂, a proportion of which will be nanoparticle sized. To assess the behaviour of engineered nanoparticle (ENP) TiO₂ in sewage and toxicology studies, Optisol (Oxonica Materials Ltd) and P25 (Evonik Industries AG), which are representative of forms used in sunscreen and cosmetic products, were used. These revealed a close association of TiO₂ ENPs with activated sludge. Using commercial information on consumption, and removal rates for sewage treatment, predictions were made for river water concentrations for sunscreen TiO₂ ENPs for the Anglian and Thames regions in Southern England. The highest predicted value from these exercises was 8.8 μg/L for the Thames region in which it was assumed that one in four people used the recommended application of sunscreen during a low flow (Q95) period. Ecotoxicological studies using potentially vulnerable species indicated that 1000 μg/L TiO₂ ENP did not affect the viability of a mixed community of river bacteria in the presence of UV light. Direct exposure to TiO₂ ENPs did not impair the immuno-effectiveness of earthworm coelomocyte cells at concentrations greatly above those predicted for sewage sludge.

Potential risks associated with the proposed widespread use of Tamiflu

Background The threat of pandemic influenza has focused attention and resources on virus surveillance, prevention, and containment. The World Health Organization has strongly recommended the use of the antiviral drug Tamiflu both to treat and prevent pandemic influenza infection. A major concern for the long-term efficacy of this strategy is to limit the development of Tamiflu-resistant influenza strains. However, in the event of a pandemic, hundreds of millions of courses of Tamiflu, stockpiled globally, will be rapidly deployed. Given its apparent resistance to biodegradation and hydrophilicity, oseltamivir carboxylate (OC), the active antiviral and metabolite of Tamiflu, is predicted to enter receiving riverwater from sewage treatment works in its active form. Objective Our objective in this study was to determine the likely concentrations of OC released into U.S. and U.K. river catchments using hydrologic modeling and current assumptions about the course and management of an influenza pandemic. Discussion We predict that high concentrations of OC (micrograms per liter) capable of inhibiting influenza virus replication would be sustained for periods of several weeks, presenting an increased risk for the generation of antiviral resistance and genetic exchange between influenza viruses in wildfowl. Owing to the apparent recalcitrance of OC in sewage treatment works, widespread use of Tamiflu during an influenza pandemic also poses a potentially significant, uncharacterized, ecotoxicologic risk in each affected nation’s waterways. Conclusion To gauge the hazard presented by Tamiflu use during a pandemic, we recommend a) direct measurement of Tamiflu persistence, biodegradation, and transformation in the environment; b) further modeling of likely drug concentrations in the catchments of countries where humans and waterfowl come into frequent close contact, and where significant Tamiflu deployment is envisaged; and c) further characterization of the risks of generating Tamiflu-resistant viruses in OC-exposed wildfowl.

Initial predictions of the concentrations and distribution of 17β-oestradiol, oestrone and ethinyl oestradiol in 3 English rivers

The application of the EXAMS model to estimate the likely distribution of the steroid oestrogens, 17β-oestradiol, oestrone and ethinyl-oestradiol in the Rivers Thames, Calder and Aire, U.K. is described. The model uses parameters estimated from laboratory measurements using material collected from each of the three rivers or from the literature. Total concentrations in the water column were predicted to be similar for 17β-oestradiol and oestrone and an order of magnitude less for ethinyl-oestradiol, reflecting the difference in the sewage input loads of the chemicals used in the models. Concentrations under average conditions were predicted to (a) be found mainly in the dissolved phase and (b) to vary between 0.21 and 0.37 ng l−1 for 17β-oestradiol, 0.27 and 0.44 ng l−1 for oestrone and 0.024 and 0.038 ng l−1 for ethinyl-oestradiol. Under low-flow conditions, predicted concentrations increased by a factor of 4 to 10 times the average concentrations at the point of discharge. Predicted degradation processes in the water column were only significant under low-flow conditions and volatilization was negligible. A simple assessment of the model sensitivity to selected parameters identified those that were most significant in determining the distribution of the chemicals.

Cytotoxic drugs in drinking water: a prediction and risk assessment exercise for the Thames catchment in the United Kingdom

Cytotoxic, also known as antineoplastic, drugs remain an important weapon in the fight against cancer. This study considers the water quality implications for the Thames catchment (United Kingdom) arising from the routine discharge of these drugs after use, down the drain and into the river. The review focuses on 13 different cytotoxic drugs from the alkylating agent, antimetabolite, and anthracycline antibiotic families. A geographic-information-system-based water quality model was used in the present study. The model was informed by literature values on consumption, excretion, and fate data to predict raw drinking water concentrations at the River Thames abstraction points at Farmoor, near Oxford, and Walton, in West London. To discover the highest plausible values, upper boundary values for consumption and excretion together with lower removal values for sewage treatment were used. The raw drinking water cytotoxic drug maximum concentrations at Walton (the higher of the two) representative of mean and low flow conditions were predicted to be 11 and 20 ng/L for the five combined alkylating agents, 2 and 4 ng/L for the three combined antimetabolites, and 0.05 and 0.10 ng/L the for two combined anthracycline antibiotics, respectively. If they were to escape into tap water, then the highest predicted concentrations would still be a factor of between 25 and 40 below the current recommended daily doses of concern. Although the risks may be negligible for healthy adults, more concern may be associated with special subgroup populations, such as pregnant women, their fetuses, and breast-feeding infants, due to their developmental vulnerability.

Principles of sound ecotoxicology.

We have become progressively more concerned about the quality of some published ecotoxicology research. Others have also expressed concern. It is not uncommon for basic, but extremely important, factors to apparently be ignored. For example, exposure concentrations in laboratory experiments are sometimes not measured, and hence there is no evidence that the test organisms were actually exposed to the test substance, let alone at the stated concentrations. To try to improve the quality of ecotoxicology research, we suggest 12 basic principles that should be considered, not at the point of publication of the results, but during the experimental design. These principles range from carefully considering essential aspects of experimental design through to accurately defining the exposure, as well as unbiased analysis and reporting of the results. Although not all principles will apply to all studies, we offer these principles in the hope that they will improve the quality of the science that is available to regulators. Science is an evidence-based discipline and it is important that we and the regulators can trust the evidence presented to us. Significant resources often have to be devoted to refuting the results of poor research when those resources could be utilized more effectively.

Do Concentrations of Ethinylestradiol, Estradiol, and Diclofenac in European Rivers Exceed Proposed EU Environmental Quality Standards?

This study used a geographic based water model to predict the environmental concentrations of three pharmaceuticals, 17α-ethinylestradiol (EE2), 17β-estradiol (E2), and diclofenac throughout European rivers. The work was prompted by the proposal of the European Community (COM(2011)876) to consider these chemicals as candidates for future control via environmental quality standards (EQS). National drug consumption information, excretion, national water use, and sewage removal rates, were used to derive per capita sewage effluent values for the European countries . For E2, excretion rates of the natural hormone and national demographics were also included. Incorporating this information into the GWAVA model allowed water concentrations throughout Europes rivers to be predicted. The mean concentration from the expected sewage discharge scenario indicated that 12% by length of Europes rivers would reach concentrations greater than the proposed 0.035 ng/L EQS for EE2. For several countries, between a quarter and a third of their total river length would fail such an EE2 EQS. For E2, just over 1% by length of rivers would reach concentrations greater than the 0.4 ng/L proposed EQS, while just over 2% by length of rivers would reach concentrations greater than the proposed EQS of 100 ng/L for diclofenac.

Rapid determination of free and conjugated estrogen in different water matrices by liquid chromatography–tandem mass spectrometry

This article describes the development of a short pre-treatment method that allows the simultaneous analysis of free estrogens (estrone, 17beta-estradiol, estriol and 17 alpha-ethynylestradiol) and their sulphate and glucuronide conjugated forms. For a range of matrices, from sewage effluent to river water, the developed methodology based on solid-phase extraction and fractionation technique with ultra-performance liquid chromatography system showed effective separation of the targeted estrogens. The detection limits of this method ranged from 0.2 to 0.8 ng L(-1) for river water. The recoveries for river water and sewage effluent varied from 63% to 127%. The problems of matrix effects and ion suppression or enhancement were allowed quantitatively for in the analysis using standard addition. The developed method was used successfully to detect estrogens and their conjugates in both raw and treated wastewater, and river water at a location in Japan. High concentrations of the free estrogens estrone, 17beta-estradiol and estriol were found in the influent (22.6, 77.2, 64.6 ng L(-1), respectively) but only E1 was still present at a high concentration in the effluent which was reflected in the downstream river concentration. Estrone-3-sulphate was detected up to 18.0 ng L(-1) in influent water sample and 1.1 ng L(-1) in downstream water. For the sulphate conjugates, removal efficiencies varied from 35 to 88%. Glucuronide conjugates were detected only once in the sewage influent.

Potential for aerobic isoproturon biodegradation and sorption in the unsaturated and saturated zones of a chalk aquifer

The potential fate and behaviour of the herbicide isoproturon, under aerobic conditions, was studied in soil, chalk and groundwater from two sites on an unconfined aquifer in Hampshire, UK. A small but significant sorption potential for isoproturon was noted in the upper chalk, suggesting that some retardation would take place in transport through the chalk. The degradation potential of the samples was studied using laboratory microcosms. Very little degradation potential appeared to exist for isoproturon in the unsaturated zone of upper chalk 3 m below the soil surface. Wide variations in degradation rates between samples from the same depth was noted. A degradation potential was noted in the chalk from shallow depths under laboratory microcosm conditions at a pesticide concentration of 100 μg l−1. Of the two sites examined, the most rapid and consistent degradation observed was associated with the groundwater rather than the chalk in the saturated zone. No significant isoproturon ring mineralisation occurred in the chalk or groundwater samples, implying that where isoproturon degradation does occur a by-product containing the phenyl ring will persist. Isoproturon degradation potential was not directly related to the moisture content, total organic carbon, ability to metabolise acetate, or number of viable bacteria present in the sample.