Environmental scenarios for the future nitrogen policy in Flanders,Belgium

The agricultural sector accounts for two thirds of nitrogen losses in Flanders, Belgium. Since 1991 both the government and the farmers have been taking measures to reduce the nitrogen surplus. Initially, the manure policy was aimed at distributing the manure surplus equally across Flanders. At the same time, the growth of livestock was stopped by a strict licensing policy, which required "command and control" measures. In recent years, the policy has switched to the use of individual target commitments by farmers. The Flemish manure policy will be tightened even more as a result of international pressures. An ex ante evaluation of possible policy options was carried out using three different scenarios spread out until 2010 (Business As Usual, Additional Measures, and Sustainable Development). To do this, a sector-economic, regionalized, environmental, comparative static, partial equilibrium, mathematical programming model of the Flemish agriculture was developed. The nitrogen emission into the agricultural soil was calculated by means of a regional soil balance. European targets can only be reached with manure processing, reduced fertilizer usage, and a strong reduction of intensive livestock breeding activities. The atmospheric deposition of nitrogen compounds will strongly decrease in 2010 if additional measures are taken. This will also result in a strong reduction of nitrous oxide emissions.     

Uncertainties in the Environmental Risk Assessment of Metals

As life has evolved in the presence of metals, the assessment of the potential adverse effects of metals on ecosystems requires a different approach than those presently used for man-made organic substances. This article provides a brief review of applications and limitations of current techniques and presents, based on recent research results, suggestions for improving the scientific relevance and accuracy of environmental risk assessments of metals. The importance of the following factors responsible for major uncertainties in current environmental risk assessments of metals are discussed: factors affecting metal bioavailability and toxicity, the potential importance of deficiency effects (for essential metals), and field extrapolation of laboratory toxicity data. Possible (regulatory) consequences of inaccurately assessing the natural background concentrations of metals and acclimatization/adaptation potential of laboratory organisms and resident communities are illustrated using examples of recent research, hypothesis development, and a probabilistic environmental risk assessment.     

Application of the Environmental Relative Moldiness Index in Finland

The environmental relative moldiness index (ERMI) metric was previously developed to quantify mold contamination in U.S. homes. This study determined the applicability of the ERMI for quantifying mold and moisture damage in Finnish residences. Homes of the LUKAS2 birth cohort in Finland were visually inspected for moisture damage and mold, and vacuumed floor dust samples were collected. An ERMI analysis including 36 mold-specific quantitative PCR assays was performed on the dust samples (n = 144), and the ERMI metric was analyzed against inspection-based observations of moisture damage and mold. Our results show that the ERMI was significantly associated with certain observations of visible mold in Finnish homes but not with moisture damage. Several mold species occurred more frequently and at higher levels in Finnish than in U.S. homes. Modification of the ERMI toward Finnish conditions, using a subsample of LUKAS2 homes with and without moisture damage, resulted in a simplified metric based on 10 mold species. The Finnish ERMI (FERMI) performed substantially better in quantifying moisture and mold damage in Finnish homes, showing significant associations with various observations of visible mold, strongest when the damage was located in the child''s main living area, as well as with mold odor and moisture damage. As shown in Finland, the ERMI as such is not equally well usable in different climates and geographic regions but may be remodeled to account for local outdoor and indoor fungal conditions as well as for moisture damage characteristics in a given country.     

Uncertainty Analysis of Pesticide Residues in Drinking Water Risk Assessment

Pesticide residues in drinking water can vary significantly from day to day. However, water quality monitoring performed under the Safe Drinking Water Act (SDWA) at most community water systems (CWSs) is typically limited to four data points per year over a few years. Due to this limited sampling, likely maximum residues may be underestimated in risk assessment. In this work, a statistical methodology is proposed to study two types of uncertainties in observed samples and their propagated effect in risk estimates. The methodology was demonstrated using data from 16 CWSs that have three independent databases of atrazine residue to estimate the uncertainty of risk in infants and children. The results showed that in 85% of the CWSs, chronic risks predicted with the proposed approach may be two- to four-folds higher than that predicted with the current approach, wheras intermediate risks may be two- to three-folds higher in 50% of the CWSs. In 12% of the CWSs, however, the proposed methodology showed a lower intermediate risk. A closed-form solution of propagated uncertainty was developed to demonstrate the number of years (seasons) of data and sampling frequency needed to reduce the uncertainty of risk estimates. In general, this methodology provided good insight into the importance of addressing uncertainty of observed water quality data and the need to predict likely maximum residues in risk assessment.     

Application and assessment of the Environmental Vulnerability Index in Greece

The Environmental Vulnerability Index (EVI) was developed by the Pacific Islands Applied Geoscience Commission as a global composite index that quantifies the vulnerability of an area's environment. Greece has been selected as reference area due to its current physical and anthropogenic conditions that may lead to environmental instabilities in the natural, social, and economic infrastructure environment. Hence, in the present approach, using data on Greece, an effort to define the range of information that the EVI may provide for the pertinent country is presented and a discussion on whether the index may be further developed is conveyed. Advantages as well as shortcomings of the Index are also delineated.     

Pesticide Use and Risk Perceptions among Farmers in Southwest Iran

Pesticide use and farmers’ perceptions of risk of unsafe use of pesticides were explored in Fars Province, Iran. One hundred and fifty-five farmers engaged in pesticide handling were selected through a proportional stratified random sampling method with age as the stratification variable. Most of the farmers were not following basic pesticide safety measures and the majority of them (about 60%) were not using any protective equipment when spraying pesticides. Based on four identified factors, which explained 58% of the total variance in risk perceptions of unsafe use of pesticides, three segments of farmers were revealed. Segment A included 30.3% of the farmers who had the lowest perceived risk of unsafe use of pesticides (i.e., they perceived unsafe use of pesticides as not so dangerous). Segment B, which was the largest segment revealed, showed intermediate perceived risk of unsafe use of pesticides and all of four factors as well. However, segment C with 16.7% of farmers, reported the highest perceived risk of unsafe use of pesticides (i.e., they perceived unsafe use of pesticides as very dangerous). To develop a more targeted agricultural extension program, selected characteristics with respect to each segment were explored and compared.     

Monetary Valuation of Emissions in Implementing Environmental Policy

At various levels of environmental policy making there is a demand to translate polluting emissions into monetary units. In the so-called reduction cost approach, based upon policy targets, polluting emissions are expressed in monetary terms by determination of the marginal unit reduction cost at the emission target level. This approach provides shadow prices for emissions by which it can be established whether a certain measure or technology belongs to the most efficient set of measures by which the policy targets can be reached. This article argues that, if clear (generic) government targets such as national emission reduction targets exist for an emission, shadow prices derived by this method are to be preferred to shadow prices derived by other methods for decisions at the project (implementation) level. By application of the reduction cost approach, implementation decisions can be made that are both cost-effective and consistent with government policy.     

Principles of Assessment of Pesticide Toxicity to Arthropods Used for Pest Control in Greenhouses

Entomological Review - The basic methodological approaches to the development of standard methods of assessment of pesticide toxicity to predatory and parasitic arthropods used as natural pest...     

Fundamental Dimensions of Environmental Risk

The current paper synthesizes theory and data from the field of life history (LH) evolution to advance a new developmental theory of variation in human LH strategies. The theory posits that clusters of correlated LH traits (e.g., timing of puberty, age at sexual debut and first birth, parental investment strategies) lie on a slow-to-fast continuum; that harshness (externally caused levels of morbidity-mortality) and unpredictability (spatial-temporal variation in harshness) are the most fundamental environmental influences on the evolution and development of LH strategies; and that these influences depend on population densities and related levels of intraspecific competition and resource scarcity, on age schedules of mortality, on the sensitivity of morbidity-mortality to the organism’s resource-allocation decisions, and on the extent to which environmental fluctuations affect individuals versus populations over short versus long timescales. These interrelated factors operate at evolutionary and developmental levels and should be distinguished because they exert distinctive effects on LH traits and are hierarchically operative in terms of primacy of influence. Although converging lines of evidence support core assumptions of the theory, many questions remain unanswered. This review demonstrates the value of applying a multilevel evolutionary-developmental approach to the analysis of a central feature of human phenotypic variation: LH strategy.     

Dispersal and Diving Adjustments of the Green Turtle Chelonia mydas in Response to Dynamic Environmental Conditions during Post-Nesting Migration

In response to seasonality and spatial segregation of resources, sea turtles undertake long journeys between their nesting sites and foraging grounds. While satellite tracking has made it possible to outline their migration routes, we still have little knowledge of how they select their foraging grounds and adapt their migration to dynamic environmental conditions. Here, we analyzed the trajectories and diving behavior of 19 adult green turtles (Chelonia mydas) during their post-nesting migration from French Guiana and Suriname to their foraging grounds off the coast of Brazil. First Passage Time analysis was used to identify foraging areas located off Ceará state of Brazil, where the associated habitat corresponds to favorable conditions for seagrass growth, i.e. clear and shallow waters. The dispersal and diving patterns of the turtles revealed several behavioral adaptations to the strong hydrodynamic processes induced by both the North Brazil current and the Amazon River plume. All green turtles migrated south-eastward after the nesting season, confirming that they coped with the strong counter North Brazil current by using a tight corridor close to the shore. The time spent within the Amazon plume also altered the location of their feeding habitats as the longer individuals stayed within the plume, the sooner they initiated foraging. The green turtles performed deeper and shorter dives while crossing the mouth of the Amazon, a strategy which would help turtles avoid the most turbulent upper surface layers of the plume. These adjustments reveal the remarkable plasticity of this green turtle population when reducing energy costs induced by migration.     

Monitoring and Risk Assessment of Pesticide Residues in Tea Samples from China

In the present study an effort was made to monitor the residue levels of 32 pesticides in tea samples collected from three representative tea districts of China during 2010 to 2012. A total of 223 samples of green tea, pu-erh tea, black tea, and oolong tea were determined using gas chromatography with mass spectrometry (GC-MS). Among 223 samples, 198 samples contained pesticide residues, and 39 samples had residue levels that were more than the European Union (EU) maximum residue limits (MRLs). The most positive and violated MLRs were observed in Oolong tea. The highest detection rates and the most often exceeding the MRLs were observed for the residues of bifenthrin. Ten pesticides were not found in the 223 tea samples. The potential health risks to consumers due to tea consumption in three representative cities were estimated. The results suggested that non-cancer hazards of organophosphorus, organochlorines, and pyrethroids and the cancer risks from exposure to hexachlorobenzene, heptachlor, chlordane, and pp’-DDT were clearly below the safe limit. Nevertheless, an investigation into continuous monitoring and tighter regulation of pesticide residues in tea samples are almost always desirable or even necessary for public health protection.     

Environmental Risk Assessment of Trifluoroacetic Acid

The Montreal Protocol was developed in 1987 in response to concerns that the chlorofluorocarbons (CFCs) were releasing chlorine into the stratosphere and that this chlorine was causing a depletion of stratospheric ozone over Antarctica. This international agreement called for a phase out of these CFCs. Industry initiated a major effort to find replacements that are safe when properly used and safe to the environment. The toxicology and environmental fate of these first generation replacements has been studied extensively. It was determined that the new substances break down in the environment to give predominantly carbon dioxide, water and inorganic salts of chlorine and fluorine. The only exception is that some substances also break down to yield trifluoroacetic acid (HTFA), a substance resistant to further degradation. Recognizing this, industry embarked on a research and assessment program to study the potential effects of trifluoroacetate (TFA) on the environment and to investigate possible degradation pathways. The results of these recently completed studies are summarized below and described in further detail in this paper. Trifluoroacetic acid is a strong organic acid with a pKa of 0.23. It is miscible with water and its low octanol/water partition coefficient (log P_ow=?2.1) indicates no potential to bioaccumulate. Industrial use is limited and environmental releases are very low. Some additional TFA will be formed from the breakdown of a few halogenated hydrocarbons, most notably HFC-134a (CF₃CH₂F), HCFC-124 (CF₃CHFCl), and HCFC-123 (CF₃CHCl₂). As these substances have only been produced in limited commercial quantities, their contribution to environmental levels has been minimal. Surprisingly, environmental measurements in many of diverse locations show existing levels of 100 to 300?ng·l^?1 in water with one site (Dead Sea) having a level of 6400?ng·l^?1. These levels cannot be accounted for based on current atmospheric sources and imply a long-term, possibly pre-industrial source. Generally, soil retention of TFA is poor although soils with high levels of organic matter have been shown to have a greater affinity for TFA when contrasted to soils with low levels of organic matter. This appears to be an adsorption phenomenon, not irreversible binding. Therefore, TFA will not be retained in soil, but will ultimately enter the aqueous compartment. Modeling of emission rates and subsequent conversion rates for precursors has led to estimates of maximum levels of TFA in rain water in the region of 0.1?µ·^?1 in the year 2020. TFA is resistant to both oxidative and reductive degradation. While there had been speculation regarding the possibility of TFA being degraded into monofluoroacetic acid (MFA), the rate of breakdown of MFA is so much higher than for TFA that any MFA formed would rapidly degrade. Therefore, there would be no buildup of MFA regardless of the levels of TFA present in the environment. Although highly resistant to microbial degradation, there have been two reports of TFA degradation under anaerobic conditions. In the first study, natural sediments reduced TFA. However, even though this work was done in replicate, the investigators and others were unable to reproduce it in subsequent studies. In the second study, radiolabeled TFA was removed from a mixed anaerobic in vitro microcosm. Limited evidence of decarboxylation has also been reported for two strains of bacteria grown under highly specific conditions. TFA was not biodegraded in a semi-continuous activated sludge test even with prolonged incubation (up to 84 days). TFA does not accumulate significantly in lower aquatic life forms such as bacteria, small invertebrates, oligochaete worms and some aquatic plants including Lemna gibba (duckweed). Some bioaccumulation was observed in terrestrial higher plants, such as sunflower and wheat. This result appeared to be related to uptake with water and then concentration due to transpiration water loss. When transferred to clean hydroponic media, some elimination of TFA was seen. Also, more than 80% of the TFA in leaves was found to be water ex-tractable, suggesting that no significant metabolism of TFA had occurred. At an exposure level of 1200?mg·l^?1 of sodium trifluoroacetate (NaTFA) — corresponding to 1000?mg·l^?1 HTFA — no effects were seen on either Brachy-danio rerio (a fish) or Daphnia magna (a water flea). With duckweed, mild effects were seen on frond increase and weight increase at the same exposure level. At a concentration of 300?mg·l^?1 no effects were observed. Toxicity tests were conducted with 11 species of algae. For ten of these species the EC50 was greater than 100?mg·l^?1. In Selenastrum capricornutum the no-effect level was 0.12?mg·l^?1. At higher levels the effect was reversible. The reason for the unique sensitivity of this strain is unknown, but a recovery of the growth rate was seen when citric acid was added. This could imply a competitive inhibition of the citric acid cycle. The effect of TFA on seed germination and plant growth has been evaluated with a wide variety of plants. Application of NaTFA at 1000?mg·l^?1 to seeds of sunflower, cabbage, lettuce, tomato, mung bean, soy bean, wheat, corn, oats and rice did not affect germination. Foliar application of a solution of 100?mg·l^?1 of NaTFA to field grown plants did not affect growth of sunflower, soya, wheat, maize, oilseed rape, rice and plantain. When plantain, wheat (varieties Katepwa and Hanno) and soya were grown in hydroponic systems containing NaTFA, no effects were seen on plantain at 32?mg·l^?1, on wheat (Katepwa) and soya at 1?mg·l^?1, or on wheat (Hanno) at 10?mg·l^?1; some effects on growth were seen at, respectively, 100?mg·l^?1, 5?mg·l^?1, 5?mg·l^?1, and 10?mg·l^?1 and above. TFA is not metabolized in mammalian systems to any great extent. It is the major final metabolite of halothane, HCFC-123 and HCFC-124. The half-life of TFA in humans is 16 hours. As expected, the acute oral toxicity of the free acid is higher than the one of the sodium salt. The inhalation LC₅₀ (2 hour exposure) for mice was 13.5?mg·l^?1 (2900?ppm) and for rats it was 10?mg·l^?1 (2140?ppm). Thus, TFA is considered to have low inhalation toxicity. The irritation threshold for humans was 54?ppm. As one would expect of a strong acid, it is a severe irritant to the skin and eye. When conjugated with protein, it has been shown to elicit an immunolog-ical reaction; however, it is unlikely that TFA itself would elicit a sensitization response. Repeat administration of aqueous solutions have shown that TFA can cause increased liver weight and induction of peroxisomes. Relative to the doses (0.5% in diet or 150?mg·kg^?1·day^?1 gavage) the effects are mild. In a series of Ames assays, TFA was reported to be non-mutagenic. Its carcinogenic potential has not been evaluated. Although TFA was shown to accumulate in amniotic fluid following exposure of pregnant animals to high levels of halothane (1200?ppm), no fetal effects were seen. Likewise, a reproduction study that involved exposure of animals to halothane at levels up to 4000?ppm for 4 hours per day, 7 days per week, resulted in no adverse effects. Given the high levels of halothane exposure, it is unlikely that environmental TFA is a reproductive or developmental hazard. Overall the toxicity of TFA has been evaluated in stream mesocosms, algae, higher plants, fish, animals and humans. It has been found to be of very low toxicity in all of these systems. The lowest threshold for any effects was the reversible effect on growth of one strain of algae, Selenastrum capricornutum, which was seen at 0.12?mg·l^?1. There is a 1000-fold difference between the no-effect concentration and the projected environmental levels of TFA from HFCs and HCFCs (0.0001?mg·l^?1). Based on available data, one can conclude that environmental levels of TFA resulting from the breakdown of alternative fluorocarbons do not pose a threat to the environment.     

The Use of Epidemiology in Environmental Risk Assessment

Epidemiology provides estimates of the concentration–response relation for environmental and occupational toxicants in the species of interest, in or close to the dose range of interest. As such, when available, they provide the primary source for risk assessments. Further information can be acquired by using modern biostatistical techniques to assess the shape of the dose response relation, examine effect modification, and assure control for confounding. These approaches are particularly effective if they are done in the context of a meta-analysis or hierarchical model. This is illustrated with examples from the air pollution literature.     

The Evolution of Conservation Management Philosophy: Science, Environmental Change and Social Adjustments in Kruger National Park

In this ‘perspectives’ article, we share experiences gained from the century-old Kruger National Park (KNP) in South Africa to illustrate the dynamic complexity of biophysical and socio-political systems, the interactions that occur between them, and the consequences for ecosystem-scale functions and resources and for their management. As in KNP, the social-ecological milieu surrounding many national parks and protected areas is changing rapidly. There will be significant managerial adjustments as human populations grow and the needs for resources accelerate. The changes, driven largely by global-scale environmental shifts as well as by new knowledge, are intimately intertwined with evolving societal perceptions, values, and expectations. Many KNP resource-related issues of the past century originated more internally and were largely environmental, whereas the emerging issues are more external and largely social. Here, we illustrate how interrelated scientific and managerial advances in integrating biophysical and social systems are acting to conserve and rehabilitate resources within KNP, and to aid in their conservation. Where appropriate, we relate these advances to similar examples in the region or other protected areas in the world. Strategies to address emerging issues are identified and discussed—and their combined effects on resource conservation and management are evaluated. In our experience the approach to conservation within KNP has been successful, despite well-intended but damaging management actions in the past. We believe that the perceived success stems from a willingness to continually incorporate new knowledge into management, to foster close working and personal associations among scientists, managers, and rangers, to acquire an intimate knowledge and understanding of the social-ecological system by the administrators as well as by the staff, and to be actively ‘forward’ thinking in an increasingly complex and uncertain world. We accept that many decisions taken today will be challenged by future managers and scientists, and we expect that some will be found wanting as emerging knowledge and continued learning shape future decisions. Further, evolving political, social, and environmental contexts may mean that protected areas will need to be managed in different ways. Therefore, we emphasize the importance of minimizing the permanency and impact of decisions so that today’s actions do not compromise future decisions when meaningful changes need to be made.

Diversity of the Phytophthora infestans population in Flanders, Belgium

A total of 94 isolates of Phytophthora infestans were collected from disease outbreaks in commercial potato crops and private gardens in 2002 and 2003. The isolates were recovered successfully from single lesions of diseased potato foliage. Not from all isolates pure cultures were obtained due to contaminations with Fusarium species and bacteria. The structure of the population was analysed phenotypically. Characteristics of the isolates included in vitro growth rate, mating type, in vitro sensitivity to the phenylamide fungicide metalaxyl-M and allozyme genotype at glucose-6-phosphate isomerase (Gpi) and peptidase (Pep) loci. Significant differences in in vitro growth rate were observed among the 52 isolates by comparing the main radial growth of the isolates after 7 days. Forty seven from the isolates tested were the Al mating type. Only one isolate was characterized as A2 mating type. Isolates with sensitive, intermediate and resistant responses to metalaxyl-M were detected in the populations. Forty isolates had a growth of less then 40 % at 5 ppm metalaxyl-M. Three isolates had a growth of less then 40 % at 100 ppm metalaxyl-M. Eight isolates had a growth of more then 40 % at 5 and 100 ppm metalaxyl-M. Cellulose acetate electrophoresis was used to examine Gpi and Pep banding pattern of the population of P. infestans attacking potato in Flanders. All the isolates tested produced the 100/100 Gpi isozyme electromorph. Five different allozyme genotypes of the Pep loci were identified: 92/92, 96/96, 100/100, 92/100, 83/100.     

Environmental Risk Management Decision-Making in a Societal Context

Recent studies point to the need for improved understanding of environmental management frameworks designed to combine qualitative public and quantitative technical inputs in decision-making processes. Flux in public perception and concern about risks imply frameworks must be iterative in nature and incorporate a variety of assessment triggers in the form of decision points. A conceptual model is proposed here to explain the de facto operation of standard risk analytic frameworks within the broader sociopolitical milieu of public policy. The model is presented as a decision flow diagram that emphasizes setting environmental management goals based on societal input and the formulation of decision criteria for selecting management actions to achieve those goals. Prospective and retrospective decision control points operate to select management options that, respectively, avoid or reduce actual or predicted effects. Feedback loops that modify risk management outcomes are identified. Technical and scientific inputs (i.e., risk analysis) are assigned an essential information role within the framework and are responsible for informing the management process with the results of appropriately conducted and reviewed investigations. The proposed model is intended primarily to indicate how environmental risk management decision-making and associated technical assessments may be influenced by social pressures. It is hoped this understanding will lead to analytical transparency and better public communication of the environmental implications of policy options.     

Equine Risk Assessment for Insecticides Used in Adult Mosquito Management

Since West Nile virus (WNV) was introduced to New York City in 1999, it has subsequently spread through the Americas, creating human and animal health risks. Our equine risk assessment focused on three pyrethroid insecticides (phenothrin, resmethrin, and permethrin), pyrethrins, and two organophosphate insecticides (malathion and naled). Piperonyl butoxide, a synergist commonly used in pyrethroids, was also assessed. The objective was to use deterministic and probabilistic risk assessment methodologies to evaluate health risks to horses from vector management tactics used for control of adult mosquitoes. Our exposure estimates were derived from the Kenaga nomogram for food deposition, AgDRIFT® for deposition onto soil and hair, AERMOD for ambient air concentrations, and PRZM-EXAMS for water concentrations. We used the risk quotient (RQ) method for our assessment with the RQ level of concern (LOC) set at 1.0. RQs were determined by comparing the exposure to no-observable-effect-levels. Acute deterministic RQs ranged from 0.0004 for phenothrin to 0.2 for naled. Subchronic deterministic RQs ranged from 0.001 for phenothrin to 0.6 for naled. The probabilistic assessment revealed estimates of deterministic acute and subchronic RQs were highly conservative. Our assessment revealed that risks to horses from adult mosquito insecticides are low and not likely to exceed the LOC.