Impact of proposed changes in IESTI equations for short-term dietary exposure to pesticides from Australian and Codex perspective

ABSTRACT

In 2015 a scientific workshop was held in Geneva, where updating the four equations for estimating the short-term dietary exposure (International Estimated Short Term Intake, IESTI) to pesticides was suggested. The impact of these proposed changes on the exposure was studied by using residue data and large portion consumption data from Codex and Australia. For the Codex data, the exposure increased by a median factor of 2.5 per commodity when changing to the proposed IESTI equations. The increase in exposure was highest for bulked and blended food commodities (case 3 equations), followed by medium-sized food commodities (case 2a equations) and small- and large-sized food commodities (case 1 and case 2b equations). For the Australian data, out of 184 maximum residue limit (MRL) large portion combinations showing acute exposures below the acute reference dose (ARfD) with the current IESTI equations, 23 exceeded the ARfD with the proposed IESTI equations (12%). The percentage exceeding the ARfD was higher for the Australian MRL large portion combinations (12% of 184) than for those of Codex (1.3% of 8,366). However, the percentage MRL loss in the Australian dataset may not be representative of all pesticide MRLs since it concerns six pesticides only, specifically selected to elucidate the potential effects of the use of the proposed IESTI equations. For the Codex data, the increase in exposure using the proposed equations resulted in a small increased loss of 2.6% of the 1,110 MRLs estimated by the Joint FAO/WHO Meeting on Pesticide Residues (JMPR): 1.4% of the MRLs were already not acceptable with the current equations, 4.0% of the MRLs were not acceptable with the newly proposed equations. Our study revealed that case 3 commodities may be impacted more by the proposed changes than other commodities. This substantiates one of the conclusions of the Geneva workshop to gather information on bulking and blending practices in order to refine MRL setting and dietary risk assessment for case 3 commodities where possible.     

Factors Influencing Local Communities’ Satisfaction Levels with Different Forest Management Approaches of Kakamega Forest, Kenya

Satisfaction of communities living close to forests with forest management authorities is essential for ensuring continued support for conservation efforts. However, more often than not, community satisfaction is not systematically elicited, analyzed, and incorporated in conservation decisions. This study attempts to elicit levels of community satisfaction with three management approaches of Kakamega forest in Kenya and analyze factors influencing them. Three distinct management approaches are applied by three different authorities: an incentive-based approach of the Forest Department (FD), a protectionist approach of the Kenya Wildlife Service (KWS), and a quasi-private incentive-based approach of Quakers Church Mission (QCM). Data was obtained from a random sample of about 360 households living within a 10-km radius around the forest margin. The protectionist approach was ranked highest overall for its performance in forest management. Results indicate that households are influenced by different factors in their ranking of management approaches. Educated households and those located far from market centers are likely to be dissatisfied with all the three management approaches. The location of the households from the forest margin influences negatively the satisfaction with the protectionist approach, whereas land size, a proxy for durable assets, has a similar effect on the private incentive based approach of the QCM. In conclusion, this article indicates a number of policy implications that can enable the different authorities and their management approaches to gain approval of the local communities.     

Frugivory is associated with low measures of plasma oxidative stress and high antioxidant concentration in free-ranging bats

Oxidative stress—an imbalance between reactive pro- and neutralising antioxidants—damages cell structures and impairs fitness-relevant traits such as longevity and reproduction. Theory predicts that feeding on diets with high antioxidant content such as fruits should reduce oxidative stress; however, there is no support of this idea in free-ranging mammals. Bats cover a large variety of ecological niches, and therefore, we asked if measures of oxidative stress are lower in species with fruit diets. We measured reactive oxygen metabolites (ROM) representing total pro-oxidants produced and antioxidants in the plasma of 33 Neotropical bat species. Species with a fruit diet showed the lowest level of ROM and the highest concentration of antioxidants, followed by omnivorous and animalivorous species. Potentially, frugivorous species ingest more antioxidants with food and thus are able to neutralise more pro-oxidants than species not feeding on fruits, resulting in an overall lower level of oxidative stress. We therefore showed for the first time that measures of oxidative stress vary according to diets in free-ranging mammals.     

Organic Contaminants from Sewage Sludge Applied to Agricultural Soils. False Alarm Regarding Possible Problems for Food Safety? (8 pp)

Goal, Scope and Background Sewage sludge produced in wastewater treatment contains large amounts of organic matter and nutrients and could, therefore, be suitable as fertiliser. However, with the sludge, besides heavy metals and pathogenic bacteria, a variety of organic contaminants can be added to agricultural fields. Whether the organic contaminants from the sludge can have adverse effects on human health and wildlife if these compounds enter the food chain or groundwater still remains a point of controversial discussion. Main Features This paper presents an overview on the present situation in Europe and a summary of some recent results on the possible uptake of organic contaminants by crops after addition to agricultural fields by sewage sludge. Results Greenhouse experiments and field trials were performed to study the degradation and uptake of organic micro-contaminants in sludge-amended agricultural soil in crops, such as barley and carrots grown in agricultural soil amended with anaerobically-treated sewage sludge from a wastewater treatment plant, but studies hitherto have revealed no immediate risks. Common sludge contaminants such as linear alkylbenzene sulphonates (LAS), nonylphenol ethoxylates (NPE), polycyclic aromatic hydrocarbons (PAH), bis(diethylhexyl) phthalate (DEHP), showed neither accumulation in soil nor uptake in plants. Discussion It is assumed that the annual amount of sewage sludge produced in Europe will increase in the future, mainly due to larger amounts of high quality drinking water needed by an increasing population and due to increasing demands for cleaner sewage water. Application of sewage sludge to agricultural soils is sustainable and economical due to nutrient cycling and disposal of sewage sludge. However, this solution also involves risks with respect to the occurrence of organic contaminants and other potentially harmful contents such as pathogens and heavy metals present in the sludge. There have been concerns that organic contaminants may accumulate in the soil, be taken up by plants and thereby transferred to humans via the food chain. Results obtained so far revealed, however, no immediate risk of accumulation of common organic sludge contaminants in soil or uptake in plants when applying sewage sludge to agricultural soil. With very high dosages of sewage sludge, there may be a risk for accumulation of very apolar contaminants, such as DEHP, to the soil. Conclusions Any conclusions on the safe use of sewage sludge in agriculture have to be drawn carefully, as the studies performed until now have been limited. Further studies are required, and before final statements can be drawn, it is imminent to study a larger variety of common crops and the effect sewage sludge application may have on a possible accumulation of organic contaminants in the crops. Furthermore, a larger variety of organic contaminants need to be studied and special focus should be given to contaminants newly introduced into the environment. Besides investigating possible plant uptake of organic contaminants, the fate of these compounds in soil after sludge application need to be monitored too. Here, special attention has to begiven to studies on degradation and the formation of degradation products, to weathering and to leaching effects on groundwater, to the application of different crops on the same field (crop rotation), to the use of full-width tillage and strip tillage, and to long term application of sewage sludge on the soil. Recommendations and Perspectives There are environmental, political as well as economical incentives to increase the agricultural application of sludge. However, such usage should be performed with care as there are also ways in which sludge fertilisation could harm the environment and human health. Recently, a new European COST Action (859) has been established covering the field of food safety and improved food quality. Part of the Action is dealing with the application of sewage sludge in agriculture. Before any political and economical measures can be taken, the pros and cons have to be sufficiently investigated on a scientific level first. ESS-Submission Editor: Prof. Elena Maestri (elena.maestri@unipr.it)     

Ethics and biodiversity offsetting

Biodiversity offsetting is an increasingly applied tool aiming to compensate for environmental damage caused by exploitation projects. Critics, however, raise concerns over the purported effectiveness of offsetting and question the ethical underpinnings and implications of offsetting. These ethical dimensions have largely been overlooked in research, which may lead to offsetting systems that fail to respect the values intended to be safeguarded. To address these dimensions, 5 ethical objections in the scientific literature were identified: offsetting violates nature's intrinsic value; losses of nature cannot be compensated for by human interventions; too little is known to make adequate trades; offsetting impedes virtuous dispositions toward nature; and offsetting has negative justice implications. We examined these objections and arguments against them based on the ethical concepts of intrinsic and instrumental values, anthropocentrism, nonanthropocentrism, and deontological, consequentialist, and virtue-ethical paradigms. Both nonanthropocentric and anthropocentric concerns were expressed in deontological, consequential, and virtue-ethical framings. Objections mostly had a deontological or virtue-ethical basis, whereas counterarguments were based on consequential reasoning, but common ground in practice is often conceivable. Based on our findings, we formulated 10 recommendations for policy makers and 5 questions for practitioners to consider. We propose, for example, that policy makers clarify aims, legislate on no-go areas, and govern the use of multipliers. We suggest that practitioners consider, for instance, how to improve case-specific knowledge and promote learning and stakeholder engagement. We hope these recommendations and questions will encourage further discussion of the ethics of biodiversity offsets and ultimately strengthen the respect for biodiversity and human-welfare values at stake in offsetting projects.