Opportunities to tackle antibiotic resistance development in the aquatic environment through the Water Framework Directive

Antibiotics are critical components of modern health care. Protecting their efficacy through managing the rise in antibiotic resistance is therefore a global concern. It is not known to what extent environmental pollution from antibiotics contributes to the development of resistance, but encountered concentrations are frequently above concentrations predicted to select for resistance. Hence, measures are needed to manage risks. Here, we analyse if the indirect health risks from antibiotics in the aquatic environment can be considered in the context of the EU Water Framework Directive and the setting of environmental quality standards (EQS). By scrutinising current legislation, we conclude that it is possible to take the indirect health risks from antimicrobial resistance into account when deriving EQS for substances with antibiotic activity. We base this on the following conclusions: (1) human health concerns can be the main driver when setting an EQS, (2) an EQS can be based on data not specified in the guidance document, and (3) there are no restrictions against establishing EQS using data on antimicrobial resistance properties. In addition, since antimicrobial resistance travel across borders, we see strong reasons to prioritise setting these EQS on the EU level over the national level. Even though there is no agreed-upon method for how to develop EQS protective against resistance selection, there are several suggestions available in the literature and a couple of examples of regulatory initiatives. Also, addressing antimicrobial resistance through the Water Framework Directive can act as a driving force for other applicable legislation where such risks are not considered. We end by providing a set of recommendations for the European Commission and the Members States' future work on addressing aquatic pollution and antimicrobial resistance.

Substances of emerging concern in Baltic Sea water: Review on methodological advances for the environmental assessment and proposal for future monitoring

The Baltic Sea is among the most polluted seas worldwide. Anthropogenic contaminants are mainly introduced via riverine discharge and atmospheric deposition. Regional and international measures have successfully been employed to reduce concentrations of several legacy contaminants. However, current Baltic Sea monitoring programs do not address compounds of emerging concern. Hence, potentially harmful pharmaceuticals, UV filters, polar pesticides, estrogenic compounds, per- and polyfluoroalkyl substances, or naturally produced algal toxins are not taken into account during the assessment of the state of the Baltic Sea. Herein, we conducted literature searches based on systematic approaches and compiled reported data on these substances in Baltic Sea surface water and on methodological advances for sample processing and chemical as well as effect-based analysis of these analytically challenging marine pollutants. Finally, we provide recommendations for improvement of future contaminant and risk assessment in the Baltic Sea, which revolve around a combination of both chemical and effect-based analyses.

Critical knowledge gaps and research needs related to the environmental dimensions of antibiotic resistance

There is growing understanding that the environment plays an important role both in the transmission of antibiotic resistant pathogens and in their evolution. Accordingly, researchers and stakeholders world-wide seek to further explore the mechanisms and drivers involved, quantify risks and identify suitable interventions. There is a clear value in establishing research needs and coordinating efforts within and across nations in order to best tackle this global challenge. At an international workshop in late September 2017, scientists from 14 countries with expertise on the environmental dimensions of antibiotic resistance gathered to define critical knowledge gaps. Four key areas were identified where research is urgently needed: 1) the relative contributions of different sources of antibiotics and antibiotic resistant bacteria into the environment; 2) the role of the environment, and particularly anthropogenic inputs, in the evolution of resistance; 3) the overall human and animal health impacts caused by exposure to environmental resistant bacteria; and 4) the efficacy and feasibility of different technological, social, economic and behavioral interventions to mitigate environmental antibiotic resistance.1.

An academic researcher's guide to increased impact on regulatory assessment of chemicals

The interactions between academic research and regulatory assessment of chemicals may in theory seem straightforward: researchers perform studies, and these studies are used by regulators for decision-making. However, in practice the situation is more complex, and many factors decide a research study's regulatory use. According to several EU chemical legislations, all available and relevant studies can be used in hazard and risk assessment of chemicals. However, in practice, standard tests conducted under GLP and sponsored and provided by industry are predominantly used. Peer-reviewed studies from independent sources are often disregarded or disputed since they often do not comply with regulatory data requirements and quality criteria. To help bridge such a gap, the aim of this paper is to give an overview of the general workings of legislation of chemicals and propose a set of actions to increase the usability of research data. In the end, this may increase the use of academic research for decision-making and ultimately result in more science-based policies. From a policy perspective, useful scientific evidence comprises those studies that are sufficiently reliable and relevant. This is not in contradiction to the aims of research and generally accepted scientific standards.

Predicting petroleum phototoxicity

Phototoxicity to Daphnia magna was studied on 14 polycyclic aromatic hydrocarbons (PAHs) and 22 petroleum products (ranging from diesel to crude oil). The phototoxicity ranking of pure PAHs was about the same as found in another study on fish gill cells in vitro (Toxicology 127 (1998) 143), suggesting that the relative acute phototoxicity does not differ significantly between different species. Most petroleum products were found to be phototoxic, although the results differ somewhat between test methods (preparation of water-accommodated fractions or petroleum ether dissolved oil slurries). The degree of phototoxicity of a sample is related to both the source and the refining process of the crude oil. The best chemical predictors found were the concentrations of eight phototoxic parent PAHs. An even simpler analytical technique suggested for initial screening would be direct measurements of "total PAH," where samples having more than 3% PAH should be studied further.

Effects of different protective agents on the phototoxicity of fluoranthene to Daphnia magna

Some compounds, accumulated by organisms, are transformed into toxic forms when irradiated with UV light. The polycyclic aromatic hydrocarbon (PAH) fluoranthene is one such compound of environmental importance. In this study on Daphnia magna, fluoranthene toxicity increased significantly after a 2 h exposure to solar-simulating UV light, if organisms were allowed to accumulate the substance for 24 h prior to irradiation. Since no enhanced toxicity was observed if the solutions were irradiated before the daphnids were added and only a slight decrease in toxicity was observed if the daphnids were transferred to pure dilution water prior to exposure, it was concluded that the acute phototoxicity of fluoranthene was predominantly due to photoactivation of accumulated or adsorbed molecules. Thus, the enhanced toxicity of fluoranthene by UV light is thought to act through the production of either singlet oxygen or free radicals. Possible effects of different protective agents (antioxidants, free radical scavengers and UV-screening compounds) were examined in two cultured populations of Daphnia magna. One population received a synthetic diet and the other dried baker's yeast. The yeast-fed population became progressively more sensitive to the photoinduced toxicity of fluoranthene, and after 14 days it was significantly more sensitive than the population that received the synthetic feed. It was not obvious whether any of the additives influenced the UV-induced toxicity significantly, although, alpha-tocopherol, a known antioxidant, was the best candidate.