Including degradation products of persistent organic pollutants in a global multi-media box model

GOAL, SCOPE AND BACKGROUND: Global multi-media box models are used to calculate the fate of persistent organic chemicals in a global environment and assess long-range transport or arctic contamination. Currently, such models assume substances to degrade in one single step. In reality, however, intermediate degradation products are formed. If those degradation products have a high persistence, bioaccumulation potential and / or toxicity, they should be included in environmental fate models. The goal of this project was to gain an overview of the general importance of degradation products for environmental fate models, and to expand existing, exposure-based hazard indicators to take degradation products into account. METHODS: The environmental fate model CliMoChem was modified to simultaneously calculate a parent compound and several degradation products. The three established hazard indicators of persistence, spatial range and arctic contamination potential were extended to include degradation products. Five well-known pesticides were selected as example chemicals. For those substances, degradation pathways were calculated with CATABOL, and partition coefficients and half-lives were compiled from literature. RESULTS: Including degradation products yields a joint persistence value that is significantly higher than the persistence of the parent compound alone: in the case of heptachlor an increase of the persistence by a factor of 58 can be observed. For other substances, the increase is much smaller (4% for alpha-HCH). The spatial range and the arctic contamination potential (ACP) can increase significantly, too: for 2,4-D and heptachlor, an increase by a factor of 2.4 and 3.5 is seen for the spatial range. However, an important increase of the persistence does not always lead to a corresponding increase in the spatial range: the spatial range of aldrin increases by less than 50%, although the persistence increases by a factor of 20 if the degradation products are included in the assessment. Finally, the arctic contamination potential can increase by a factor of more than 100 in some cases. DISCUSSION: Influences of parent compounds and degradation products on persistence, spatial range and ACP are discussed. Joint persistence and joint ACP reflect similar characteristics of the total environmental exposure of a substance family (i.e., parent compound and all its degradation products). CONCLUSIONS: The present work emphasizes the importance of degradation products for exposure-based hazard indicators. It shows that the hazard of some substances is underestimated if the degradation products of these substances are not included in the assessment. The selected hazard indicators are useful to assess the importance of degradation products. RECOMMENDATIONS AND PERSPECTIVES: It is suggested that degradation products be included in hazard assessments to gain a more accurate insight into the environmental hazard of chemicals. The findings of this project could also be combined with information on the toxicity of degradation products. This would provide further insight into the importance of degradation products for environmental risk assessments.     

Haloacetic acids in the aquatic environment. Part II: ecological risk assessment

Haloacetic acids (HAAs) are environmental contaminants found in aquatic ecosystems throughout the world as a result of both anthropogenic and natural production. The ecological risk posed by these compounds to organisms in freshwater environments, with a specific focus on aquatic macrophytes, was characterized. The plants evaluated were Lemna gibba, Myriophyllum spicatum and M. sibiricum and the HAAs screened were monochloroacetic acid (MCA), dichloroacetic acid (DCA), trichloroacetic acid (TCA), trifluoroacetic acid (TFA) and chlorodifluoroacetic acid (CDFA). Laboratory toxicity data formed the basis of the risk assessment, but field studies were also utilized. The estimated risk was calculated using hazard quotients (HQ), as well as effect measure distributions (EMD) in a modified probabilistic ecological risk assessment. EMDs were used to estimate HAA thresholds of toxicity for use in HQ assessments. This threshold was found to be a more sensitive measure of low toxicity than the no observed effect concentrations (NOEC) or the effective concentration (EC10). Using both deterministic and probabilistic methods, it was found that HAAs do not pose a significant risk to freshwater macrophytes at current environmental concentrations in Canada, Europe or Africa for both single compound and mixture exposures. Still, HAAs are generally found as mixtures and their potential interactions are not fully understood, rendering this phase of the assessment uncertain and justifying further effects characterization. TCA in some environments poses a slight risk to phytoplankton and future concentrations of TFA and CDFA are likely to increase due to their recalcitrant nature, warranting continued environmental surveillance of HAAs.     

Sensitivity of schemes for ecotoxicological hazard ranking of chemicals

Data from an environmental hazard profile, including different tests on accumulation and degradation as well as Daphnia acute toxicity were used for a classification of chemicals into three categories: High hazard potential, uncertain hazard potential, and low likelyhood of environmental hazard. Giving the used evaluation factors different weights, leads to a modification in classification.     

A multispecies study to assess the toxic and genotoxic effect of pharmaceuticals: furosemide and its photoproduct

Pharmaceutical products for humans and animals, as well as their related metabolites end up in the aquatic environment after use. Recent investigations show that concentrations of pharmaceuticals are detectable in the order of ng/l-mug/l in municipal wastewater, groundwater and also drinking water. Little is known about the effects, and the hazard of long-term exposure to low concentrations of pharmaceuticals for non-target aquatic organisms. This study was designed to assess the ecotoxicity of furosemide, a potent diuretic agent, and its photoproduct in the aquatic environment. Bioassays were performed on bacteria, algae, rotifers and microcrustaceans to assess acute and chronic toxicity, while the SOS Chromotest and the Ames test were utilized to detect the genotoxic potential of the investigated compounds. A first approach to risk characterization was to calculate the environmental impact of furosemide by measured environmental concentration and predicted no effect concentration ratio (MEC/PNEC). To do so we used occurrence data reported in the literature and our toxicity results. The results showed that acute toxicity was in the order of mg/l for the crustaceans and absent for bacteria and rotifers. Chronic exposure to these compounds caused inhibition of growth population on the consumers, while the algae did not seem to be affected. A mutagenic potential was found for the photoproduct compared to the parental compound suggesting that byproducts ought to be considered in the environmental assessment of drugs. The risk calculated for furosemide suggested its harmlessness on the aquatic compartment.     

The EU environmental policy context for monitoring for and with raptors in Europe

This paper outlines the importance of the policy context for monitoring with and for raptors, and, conversely, of the importance of such monitoring for policy. It then outlines two key areas of European Union (EU) environmental policy most relevant to monitoring for and with raptors, namely biodiversity policy and pollution policy. For each of the policy areas, the pertinent objectives and actions of the current EU policy are identified, and their relevance for raptor monitoring is discussed. The potential contribution of raptor monitoring to the further development of these policy areas is also addressed.     

Synthesis of environmentally relevant fluorinated surfactants--a review

In the past years there has been a growing interest in fluorinated persistent organic pollutants such as perfluorooctanesulfonic acid, perfluorooctanesulfonamides, perfluorinated carboxylic acids and fluorotelomer alcohols. Although these compounds have probably been present in the environment for many decades, we are only now beginning to realize that these environmental contaminants may have serious environmental and health effects. This article gives a state-of-the-art review of synthetic approaches that have been employed for the synthesis of these environmentally relevant fluorinated compounds. Perfluorooctanesulfonic acid derivatives, in particular, pose a problem because only a few perfluorooctanesulfonic acid derivatives are available from commercial sources--a fact that limits the ability of researchers worldwide to further study these compounds. Because of the limited literature available, this article also describes synthetic approaches for shorter chain homologues or perfluoroether analogues that can potentially be applied for the synthesis of perfluorooctanesulfonic acid derivatives. The preparation of typical starting materials for the synthesis of perfluorooctanesulfonic acid derivatives such as the perfluoroalkanesulfonyl fluorides and chlorides will be discussed. Subsequently, their conversion into relevant perfluoroalkane sulfonate salts (R(F)SO3M), sulfonamides (R(F)SO2NH2), N-alkyl sulfonamides (R(F)SO2NHR, R = alkyl), N,N-dialkyl sulfonamides (R(F)SO2NR2, R = alkyl), sulfonamidoethanol (R(F)SO2NRCH2CH2OH, R = -H, -CH3 or -C2H5) and sulfonamidoacetates (R(F)SO2NRCH2CO2H, R = -H, -CH3 or -C2H5) will be described. Many perfluorinated carboxylic acids and fluorotelomer alcohols are available from commercial sources. The review of the synthesis of these two classes of fluorinated compounds includes a review of their industrial synthesis and the synthesis of relevant degradation products.     

Toxicological evaluation for the hazard assessment of tire crumb for use in public playgrounds

Disposal of used tires has been a major problem in solid waste management. New uses will have to be found to consume recycled tire products. One such proposed use is as ground cover in playgrounds. However, concern has been expressed regarding exposure of children to hazardous chemicals and the environmental impact of such chemicals. We designed a comprehensive hazard assessment to evaluate and address potential human health and environmental concerns associated with the use of tire crumb in playgrounds. Human health concerns were addressed using conventional hazard analyses, mutagenicity assays, and aquatic toxicity tests of extracted tire crumb. Hazard to children appears to be minimal. Toxicity to all aquatic organisms (bacteria, invertebrates, fish, and green algae) was observed; however, this activity disappeared with aging of the tire crumb for three months in place in the playground. We conclude that the use of tire crumb in playgrounds results in minimal hazard to children and the receiving environment.     

Biodegradation of persistent environmental pollutants by Arthrobacter sp.

Persistent environmental pollutants are a growing problem around the world. The effective control of the pollutants is of great significance for human health. Some microbes, especially Arthrobacter, can degrade pollutants into nontoxic substances in various ways. Here, we review the biological properties of Arthrobacter adapting to a variety of environmental stresses, including starvation, hypertonic and hypotonic condition, oxidative stress, heavy metal stress, and low-temperature stress. Furthermore, we categorized the Arthrobacter species that can degrade triazines, organophosphorus, alkaloids, benzene, and its derivatives. Metabolic pathways behind the various biodegradation processes are further discussed. This review will be a helpful reference for comprehensive utilization of Arthrobacter species to tackle environmental pollutants.

     

Effects of teflubenzuron on sediment processing by members of the Capitella species-complex

The cosmopolitan deposit-feeding polychaete Capitella is widely used as an indicator of organic pollution and plays an important role in waste recycling at aquaculture sites. Teflubenzuron is currently employed by salmon farms as an in-feed compound to control ectoparasite infestations. Its occurrence in sediments could pose a hazard to local sediment infauna. A bioassay to investigate the effects of exposing Capitella sp I and Capitella sp B to sediment spiked with environmentally relevant concentrations of teflubenzuron (8.4, 25 and 41.8 microg/g dry wt. sediment) is described. No mortality was recorded for Capitella sp I, but increasing teflubenzuron concentrations significantly reduced egestion rates. Capitella sp B exhibited mortality, although egestion was not affected. These results using Capitella spp. indicated that teflubenzuron could affect the rate of sediment processing by polychaetes close to fish farms treated with this compound. Further studies are recommended to assess the potential of contaminants in aquaculture wastes.     

Toxicological Evaluation for the Hazard Assessment of Tire Crumb for Use in Public Playgrounds

Abstract

Disposal of used tires has been a major problem in solid waste management. New uses will have to be found to consume recycled tire products. One such proposed use is as ground cover in playgrounds. However, concern has been expressed regarding exposure of children to hazardous chemicals and the environmental impact of such chemicals. We designed a comprehensive hazard assessment to evaluate and address potential human health and environmental concerns associated with the use of tire crumb in playgrounds. Human health concerns were addressed using conventional hazard analyses, mutagenicity assays, and aquatic toxicity tests of extracted tire crumb. Hazard to children appears to be minimal. Toxicity to all aquatic organisms (bacteria, invertebrates, fish, and green algae) was observed; however, this activity disappeared with aging of the tire crumb for three months in place in the playground. We conclude that the use of tire crumb in playgrounds results in minimal hazard to children and the receiving environment.     

Evaluation of soil ecotoxicity tests with functional endpoints for the risk assessment of plant protection products

This paper outlines the state-of-the-art in discussing tests with functional endpoints for the soil compartment for regulatory purposes. In spite of the fact that organic matter decomposition is one of the most important functions in the soil ecosystem, this process has not been the subject of a test requirement for risk assessment of plant protection products until very recently. Since EU Directive 91/414/EEC concerning the placing of plant protection products on the market requires in its Annex III, point 10.6.2 (entitled “Effects on other soil, non-target macro-organisms”), the evaluation of effects on organic matter breakdown, there is an urgent need to fulfil this requirement. The use of functional endpoints in terrestrial model ecosystems is also under discussion in the framework of the notification process for chemicals. Four potential methods (bait-lamina-test, litterbag test, minicontainer test, cotton-strip assay) taken from ecological literature are briefly reviewed and evaluated in this paper using several defined criteria regarding their usefulness for registration purposes. In this context, areas for further research are identified. The insecticide Dimilin (a.i. diflubenzuron) is used as an example to show how such a test improves risk assessment. Therefore, it is strongly recommended that a guidance paper describing the main principles of at least one test method on organic matter decomposition should be written in order to realise the EU requirement.     

Screening organic micropollutants in surface waters by SPE extraction and ecotoxicological testing

Complex mixtures of toxic substances occurring in surface waters are difficult to characterise by chemical analyses because each compound occurs at a very low concentration and requires a specific analytical method to be identified. Ecotoxicological tests on water extracts can be used as a screening tool to evaluate quickly and simply the overall quality of a water body with regard to micropollutant contamination. In this work, a pre-concentration procedure based on solid-phase extraction (SPE), suitable for both biological testing and analytical determination, is proposed. The extraction procedure is an improved version of a methodology used to evaluate the toxicity of organic micropollutants occurring in surface waters. It offers the advantage of using disposable commercial cartridges, which are easier to manage than the columns prepared with macromolecular resins. Water extracts from two representative Italian rivers, characterised by a different gradient of potential contamination and prepared according to the new concentration techniques, are used. The acute toxicity of the water extracts is tested on Daphnia magna and the bioluminescence inhibition in Vibrio fischeri. Criteria based on the concentration factor (CF) are proposed for assessing the hazard to aquatic life due to the exposure to toxic substances in surface waters. The aim of hazard ranking is to focus analytical efforts towards those samples that show the highest toxic potential.     

An environmental fate, exposure and risk assessment of ethylene oxide from diffuse emissions

Ethylene oxide (EO) is mainly used as a chemical intermediate and as a fumigant and sterilizing agent. Through its manufacturing and intended uses, EO may be released into the environment. Therefore, an assessment of the environmental significance of those potential emissions was conducted. Data were collected describing pertinent physical properties, degradation and other loss mechanisms that control the fate of EO in the environment. Available aquatic and terrestrial ecotoxicity data were assembled and used as the basis of calculating critical toxicity values to characterize hazard. Environmental compartment concentrations of EO were calculated using Level III fugacity-based modeling. Six scenarios were developed to account for different climatic conditions in various portions of the US. Finally, potential regional-scale risks to aquatic and terrestrial wildlife were determined. In the conceptual model that was developed in this assessment, EO diffuses into air, partitions between environmental compartments, is transported out of the different compartments via advection, and undergoes abiotic and biological degradation within each compartment. All known emissions within the continental USA were assumed to enter a modeled region roughly the size of the State of Ohio. Organisms (receptors) were assumed to dwell in both terrestrial and aquatic compartments. Receptors were assumed to include small mammals, soil invertebrates, water column (pelagic) organisms, and sediment benthos. The goal of this assessment was to characterize any potential adverse risks to terrestrial and aquatic wildlife populations. Hazard Quotients (HQ) were calculated by dividing predicted concentrations of EO in air, water, sediment, and soil by their critical toxicity values. Maximum calculated HQ values in air were 1.52x10(-7), in water were 1.17x10(-5), in sediment were 2.25x10(-4), and in soil were 1.37x10(-5). The results of this assessment suggest that EO as currently manufactured and used does not pose adverse risks to aquatic or terrestrial wildlife. In all cases, the HQ values were much less than the maximum desired HQ value of 1.0 (4,400-6,600,000 times), indicating that the potential for diffuse emissions of EO to pose adverse environmental risks is quite low.     

Effects of bensulfuron-methyl and cinosulfuron on growth of four freshwater species of phytoplankton

The acute toxicity of sulfonylurea herbicides bensulfuron-methyl and cinosulfuron was tested on the five species of freshwater phytoplankton: Scenedesmus acutus, Scenedesmus subspicatus, Chlorella vulgaris and Chlorella saccharophila. Herbicide concentrations eliciting a 50% growth reduction over 96 h (EC50) ranged from 8 to 104 mg/l for cinosulfuron and from 0.015 to 6.2 mg/l for bensulfuron-methyl. The pesticides bensulfuron-methyl, atrazine and benthiocarb were more toxic than cinosulfuron, chlorsulfuron, molinate, fenitrothion and pyridaphenthion in a toxicity study with the same algal species. The transformation of effective concentrations of bensulfuron-methyl and cinosulfuron and other pesticides, obtained from toxicity measurements, into percent of the saturation level in water is used as a first evaluation of potential hazard to aquatic systems. The herbicides cinosulfuron, methyl-bensulfuron, atrazine and chlorsulfuron were more dangerous than the herbicides benthiocarb and molinate and than the insecticides fenitrothion and pyridaphenthion, in a study of hazard evaluation. The two species of Chlorella were more tolerant to both herbicides than the two species of Scenedesmus. A potential environmental hazard of sulfonylurea herbicides to aquatic systems has to be expected even at low environmental concentrations.     

Generic scenario for the impact of cooling lubricants into the hydrosphere

According to directive 93/67/EEC of the European Commission, this paper deals with the generic exposition evaluation of the environmental concentration of cooling Lubricant chemicals from the metal working industry into the hydrosphere. After considering the relevant life-cycle steps and the selection of a representative point source for the 'reasonable worst case', the emission per day Elocal(water) is determined. It leads to the predicted environmental concentration (PEClocal(water)) for the local stage in the compartment water. In order to gain the PEClocal(water) for an example--a corrosion inhibitor as additive in a cooling lubricant--, the relevant emission paths and the corresponding representative point source are described for the reasonable worst case. For non-water-miscible cooling lubricants, none of the operations in the life cycle leads to a release into the compartment water. To evaluate the hazard potential for cooling lubricant chemicals, the complete risk assessment has to be done. Also, the assessment has to be done for all high production volume chemicals, new substances and existing hazard chemicals. This means that even industrial categories like chemicals used in the textile industry or biocides and others have to be evaluated.     

Pharmacopollution and Household Waste Medicine (HWM): how reverse logistics is environmentally important to Brazil

Pharmacopollution is a public health and environmental outcome of some active pharmaceutical ingredients (API) and endocrine-disrupting compounds (EDC) dispersed through water and/or soil. Its most important sources are the pharmaceutical industry, healthcare facilities (e.g., hospitals), livestock, aquaculture, and households (patients’ excretion and littering). The last source is the focus of this article. Research questions are “What is the Household Waste Medicine (HWM) phenomenon?”, “How HWM and pharmacopollution are related?”, and “Why is a reverse logistic system necessary for HWM in Brazil?” This article followed the seven steps proposed by Rother (2007) for a systematic review based on the Cochrane Handbook and the National Health Service (NHS) Center for Reviews Dissemination (CDR) Report. The HWM phenomenon brings many environmental, public health, and, social challenges. The insufficient data is a real challenge to assessing potential human health risks and API concentrations. Therefore, the hazard of long-term exposure to low concentrations of pharmacopollutants and the combined effects of API mixtures is still uncertain. HWM are strongly related to pharmacopollution, as this review shows. The Brazilian HWM case is remarkable because it is the fourth pharmaceutical market (US$ 65,971 billion), with a wide number of private pharmacies and drugstores (3.3: 10,000 pharmacy/inhabitants), self-medication habits, and no national take-back program. The HWM generation is estimated in 56.6 g/per capita, or 10,800 t/year. The absence of a reverse logistics for HWM can lead to serious environmental and public health challenges. The sector agreement for HWM is currently under public consultation.     

Conflicts between biodiversity conservation and human activities in the central and eastern European countries

Conflicts between the conservation of biodiversity and other human activities have been and continue to be of increasing concern in the European Union, often having important political, economic, and environmental repercussions. These conflicts have been addressed in the European Union by using a wide array of top down and bottom up tools, with varying degrees of success. A new challenge is now facing Europe with the integration of 10 new countries in the European Union (EU) and an additional range of biodiversity-rich habitats placed under EU legislation. The rich biodiversity of the central and eastern European countries (CEEC) is likely to be threatened by some aspects of the integration process, and conflicts between the conservation of biodiversity and other human activities are expected. In this paper, we review certain existing conflicts between biodiversity conservation and human activities in the CEEC, expected conflicts associated with integration to the EU, particularly in terms of new policy and legislation implementation, and, finally, explore possible conflict management options.     

Chlorophenols and other related derivatives of environmental concern: properties, distribution and microbial degradation processes

Chlorophenols are chlorinated aromatic compound structures and are commonly found in pesticide preparations as well as industrial wastes. They are recalcitrant to biodegradation and consequently persistent in the environment. A variety of chlorophenols derivatives compounds are highly toxic, mutagenic and carcinogenic for living organisms. Biological transformation by microorganisms is one of the key remediation options that can be exploited to solve environmental pollution problems caused by these notorious compounds. The key enzymes in the microbial degradation of chlorophenols are the oxygenases and dioxygenases. These enzymes can be engineered for enhanced degradation of highly chlorinated aromatic compounds through directed evolution methods. This review underscores the mechanisms of chlorophenols biodegradation with the view to understanding how bioremediation processes can be optimized for cleaning up chloroaromatic contaminated environments.     

Eco-certification of Farmed Seafood: Will it Make a Difference?

Eco-certification is widely considered a tool for reducing environmental impacts of aquaculture, but what are the likely environmental outcomes for the world’s fastest growing animal-food production sector? This article analyzes a number of eco-certification schemes based on species choice, anticipated share of the global seafood market, size of eligible producers, and targeted environmental impacts. The potential of eco-certification to reduce the negative environmental impacts of aquaculture at scale presently appears uncertain as: (a) certification schemes currently focus on species predominantly consumed in the EU and US, with limited coverage of Asian markets; (b) the share of certified products in the market as currently projected is too low; (c) there is an inequitable and non-uniform applicability of certification across the sector; (d) mechanisms or incentives for improvement among the worst performers are lacking; and (e) there is incomplete coverage of environmental impacts, with biophysical sustainability and ecosystem perspectives generally lacking.     

Environmental contamination, human exposure and body loadings of perfluorooctane sulfonate (PFOS), focusing on Asian countries

Perfluorinated compounds (PFCs) are man-made fluorinated hydrocarbons, which are very persistent in the environment. Since the early 1980s, the usage of PFCs has sharply increased for a wide array of industrial and commercial applications. Being the most important PFC, perfluorooctane sulfonate (PFOS) has received much attention. In the past decades, increasing surveys have been focused on this compound, to study its sources, fates and effects in the environment. According to the large production volume and wide usage in industrial and commercial products in the past, PFOS can be detected in various environmental media and matrix, even in human tissues. This article attempted to review the current status of PFOS contaminations in Asia, focusing on water systems, sediments, wide animals and human tissues. A special section is devoted to examine the pathways of human exposure to this compound, as well as human body loadings of PFOS and their possible association with diseases.