Wageningen University and Research Centre

About: Wageningen University and Research Centre is a education organization based out in Wageningen, Netherlands. It is known for research contribution in the topics: Population & Sustainability. The organization has 23474 authors who have published 54833 publications receiving 2608897 citations.

Reproductive and Developmental Toxicity of Phthalates

Abstract: The purposes of this review are to (1) evaluate human and experimental evidence for adverse effects on reproduction and development in humans, produced by exposure to phthalates, and (2) identify knowledge gaps as for future studies. The widespread use of phthalates in consumer products leads to ubiquitous and constant exposure of humans to these chemicals. Phthalates were postulated to produce endocrine-disrupting effects in rodents, where fetal exposure to these compounds was found to induce developmental and reproductive toxicity. The adverse effects observed in rodent models raised concerns as to whether exposure to phthalates represents a potential health risk to humans. At present, di(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DBP), and butyl benzyl phthalate (BBP) have been demonstrated to produce reproductive and developmental toxicity; thus, this review focuses on these chemicals. For the general population, DEHP exposure is predominantly via food. The average concentrations of phthalates are highest in children and decrease with age. At present, DEHP exposures in the general population appear to be close to the tolerable daily intake (TDI), suggesting that at least some individuals exceed the TDI. In addition, specific high-risk groups exist with internal levels that are several orders of magnitude above average. Urinary metabolites used as biomarkers for the internal levels provide additional means to determine more specifically phthalate exposure levels in both general and high-risk populations. However, exposure data are not consistent and there are indications that secondary metabolites may be more accurate indicators of the internal exposure compared to primary metabolites. The present human toxicity data are not sufficient for evaluating the occurrence of reproductive effects following phthalate exposure in humans, based on existing relevant animal data. This is especially the case for data on female reproductive toxicity, which are scarce. Therefore, future research needs to focus on developmental and reproductive endpoints in humans. It should be noted that phthalates occur in mixtures but most toxicological information is based on single compounds. Thus, it is concluded that it is important to improve the knowledge of toxic interactions among the different chemicals and to develop measures for combined exposure to various groups of phthalates.

Does aquaculture add resilience to the global food system

Abstract: Aquaculture is the fastest growing food sector and continues to expand alongside terrestrial crop and livestock production. Using portfolio theory as a conceptual framework, we explore how current interconnections between the aquaculture, crop, livestock, and fisheries sectors act as an impediment to, or an opportunity for, enhanced resilience in the global food system given increased resource scarcity and climate change. Aquaculture can potentially enhance resilience through improved resource use efficiencies and increased diversification of farmed species, locales of production, and feeding strategies. However, aquaculture’s reliance on terrestrial crops and wild fish for feeds, its dependence on freshwater and land for culture sites, and its broad array of environmental impacts diminishes its ability to add resilience. Feeds for livestock and farmed fish that are fed rely largely on the same crops, although the fraction destined for aquaculture is presently small (∼4%). As demand for high-value fed aquaculture products grows, competition for these crops will also rise, as will the demand for wild fish as feed inputs. Many of these crops and forage fish are also consumed directly by humans and provide essential nutrition for low-income households. Their rising use in aquafeeds has the potential to increase price levels and volatility, worsening food insecurity among the most vulnerable populations. Although the diversification of global food production systems that includes aquaculture offers promise for enhanced resilience, such promise will not be realized if government policies fail to provide adequate incentives for resource efficiency, equity, and environmental protection.

Biodiversity effects on soil processes explained by interspecific functional dissimilarity.

Abstract: The loss of biodiversity can have significant impacts on ecosystem functioning, but the mechanisms involved lack empirical confirmation. Using soil microcosms, we show experimentally that functional dissimilarity among detritivorous species, not species number, drives community compositional effects on leaf litter mass loss and soil respiration, two key soil ecosystem processes. These experiments confirm theoretical predictions that biodiversity effects on ecosystem functioning can be predicted by the degree of functional differences among species.

El Niño effects on the dynamics of terrestrial ecosystems.

Abstract: New studies are showing that the El Nino Southern Oscillation (ENSO) has major implications for the functioning of different ecosystems, ranging from deserts to tropical rain forests. ENSO-induced pulses of enhanced plant productivity can cascade upward through the food web invoking unforeseen feedbacks, and can cause open dryland ecosystems to shift to permanent woodlands. These insights suggest that the predicted change in extreme climatic events resulting from global warming could profoundly alter biodiversity and ecosystem functioning in many regions of the world. Our increasing ability to predict El Nino effects can be used to enhance management strategies for the restoration of degraded ecosystems.

The environmental sustainability of insects as food and feed. A review

Abstract: With a growing world population, increasingly demanding consumers, and a limited amount of agricultural land, there is an urgent need to find alternatives to conventional meat products. Livestock production is, moreover, a leading cause of anthropogenic-induced climate change. To mediate this, more sustainable diets are needed, with reduced meat consumption or the use of alternative protein sources. Insects are promoted as human food and animal feed worldwide. In tropical countries, edible insects are harvested from nature, but overexploitation, habitat changes, and environmental contamination threaten this food resource. Therefore, sustainable harvesting practices need to be developed and implemented. We provide examples of (1) aquatic insects whose populations are threatened by pollution, (2) caterpillar species in Africa that are disappearing due to overexploitation and habitat change, (3) edible insects species that are considered pests in agro-ecosystems, and (4) edible insect species that can be conserved and enhanced in forest management systems. Insect farming can be conducted either on small-scale farms or in large-scale industrialized rearing facilities. We review the environmental sustainability of insect farming compared to livestock production. The major environmental advantages of insect farming compared to livestock production are as follows: (1) less land and water is required; (2) greenhouse gas emissions are lower; (3) insects have high feed conversion efficiencies; (4) insects can transform low-value organic by-products into high-quality food or feed; and (5) certain insect species can be used as animal feed or aqua feed. For instance, they can replace fish meal, which is becoming increasingly scarce and expensive. However, edible insect species intended for production should be screened for risks to humans, animals, plants, and biodiversity.