Inclusion of Waste Collectors in Brazil: A posteriori study of cooperative interventions

In developing countries the informal waste collectors provide important social, environmental, and economic services to society, but are often not recognized nor compensated for the work. This research paper addresses the importance of the integration of informal waste collectors in waste management systems. This phenomenon is especially relevant in Brazil with a comprehensive urban solid waste law enacted in 2010 that promotes the integration of informal waste collectors, selective collection, and reverse logistics, among others. With a decentralized management, municipalities are the responsible executors of waste management. In the implementation of the legal framework, there are practical obstacles that still need to be overcome, such as engagement from all stakeholders and adequate compensation for services by sectorial and industrial sectors, corruption and lack of institutional capacity. This paper, a posteriori evaluation, discusses the integration of the informal sector of waste collectors in Brazil as a mean to improve waste management and poverty reduction resulting in greater social, environmental and economic benefits to society, the key cornerstones to sustainable development. By applying an analytical framework and the rapid assessment tool InteRa to a number of cooperatives in the South Eastern region of Brazil, and interviewing key stakeholders, the current situation in Brazil is brought to light

Effects of redox cycling compounds on DT diaphorase activity in the liver of rainbow trout (Oncorhynchus mykiss)

BACKGROUND: DT diaphorase (DTD; NAD(P)H:quinone oxidoreductase; EC 1.6.99.2) catalyses the two electron reduction of quinones, thus preventing redox cycling and consequently quinone dependent production of reactive oxygen species. In rat and mouse, a wide range of chemicals including polyaromatic hydrocarbons, azo dyes and quinones induces DTD. Bifunctional compounds, such as β-naphthoflavone (β-NF) and benzo(a)pyrene (B(a)P), induce DTD together with CYP1A and phase II enzymes by a mechanism involving the aryl hydrocarbon receptor (AHR). Monofunctional induction of DTD is mediated through the antioxidant response element and does not lead to the induction of AHR dependent enzymes, such as CYP1A. The aim of this study was to investigate the effects of prooxidants (both bifunctional and monofunctional) on the activity of hepatic DTD in rainbow trout (Oncorhynchus mykiss) in order to evaluate DTD suitability as a biomarker. We also investigated the effect of β-NF on hepatic DTD activity in perch (Perca fluviatilis), shorthorn sculpin (Myoxocephalus scorpius), eelpout (Zoarces viviparus), brown trout (Salmo trutta) and carp (Cyprinus carpio). In addition, the effect of short term exposure to prooxidants on catalase activity was investigated. RESULTS: In rainbow trout, hepatic DTD activity is induced by the bifunctional AHR agonists β-NF and B(a)P and the monofunctional inducers naphthazarin, menadione and paraquat. Although exposure to both B(a)P and β-NF led to a strong 7-ethoxyresorufin-O-deethylase (EROD) induction, none of the monofunctional compounds affected the rainbow trout EROD activity. DTD was not induced by β-NF in any of the other fish species. Much higher DTD activities were observed in rainbow trout compared to the other fish species. Catalase activity was less responsive to short term exposure to prooxidants compared to DTD. CONCLUSION: Since rainbow trout hepatic DTD activity is inducible by both monofunctional and bifunctional inducers, it is suggested that rainbow trout DTD may be regulated by the same mechanisms, as in mammals. The fact that DTD is inducible in rainbow trout suggests that the enzyme may be suitable as a part of a biomarker battery when rainbow trout is used in environmental studies. It appears as if DTD activity in rainbow trout is higher and inducible compared to the other fish species studied

Effects of pesticides and metals on penaeid shrimps in Maputo Bay, Mozambique – A field study

Estuaries are important nursery areas for many species and these habitats are often affected by anthropogenic activities. We investigate possible negative effects of pesticides and metals on penaeid shrimps in Maputo Bay, Mozambique. Shrimps and water samples were collected in three estuaries and one coastal area for biomarker and chemical analysis. Acetylcholinesterase (AChE) and glutathione-S transferase activities were analysed as biomarkers for pollutants. 37 different pesticides were analysed in water samples and shrimp muscle tissue was analysed for 10 metals. Risk assessment showed that the environmental thresholds were exceeded for several herbicides in three of four of the assessed nursery areas. Lower AChE activities were detected in shrimps captured close to an agriculture area and this location had the lowest shrimp densities. Metal analysis in shrimp showed low levels. Despite localized effects, results highlight the need to improve the regulation of pollutants in the Esp\uedrito Santo estuary in Maputo bay

Thyroid function and immune status in perch (Perca fluviatilis) from lakes contaminated with PFASs or PCBs

The environment contains a multitude of man-made chemicals, some of which can act as endocrine disruptors (EDCs), while others can be immunotoxic. We evaluated thyroid disruption and immunotoxic effects in wild female perch (Perca fluviatilis) collected from two contaminated areas in Sweden; one site contaminated with perand polyfluoroalkyl substances (PFASs) and two sites contaminated with polychlorinated biphenyls (PCBs), with one reference site included for each area. The hepatic mRNA expression of thyroid receptors alpha and beta, and the thyroid hormone metabolising iodothyronine deiodinases (dio1, dio2 and dio3) were measured using real-time PCR, while the levels of thyroid hormone T3 in plasma was analysed using a radioimmunoassay. In addition, lymphocytes, granulocytes, and thrombocytes were counted microscopically. Our results showed lower levels of T3 as well as lower amounts of lymphocytes and granulocytes in perch collected from the PFAS-contaminated site compared to reference sites. In addition, expressions of mRNA coding for thyroid hormone metabolising enzymes (dio2 and dio3) and thyroid receptor alpha (thra) were significantly different in these fish compared to their reference site. For perch collected at the two PCB-contaminated sites, there were no significant differences in T3 levels or in expression levels of the thyroid-related genes, compared to the reference fish. Fish from one of the PCB-contaminated sites had higher levels of thrombocytes compared with both the second PCB lake and their reference lake; hence PCBs are unlikely to be the cause of this effect. The current study suggests that lifelong exposure to PFASs could affect both the thyroid hormone status and immune defence of perch in the wild

Influence of Aging on Bioaccumulation and Toxicity of Copper Oxide Nanoparticles and Dissolved Copper in the Sediment-Dwelling Oligochaete <i>Tubifex tubifex</i>:A Long-Term Study Using a Stable Copper Isotope

For engineered metal nanoparticles (NPs), such as copper oxide (CuO) NPs, the sediment is recognized as a major compartment for NP accumulation. Sediment-dwelling organisms, such as the worm Tubifex tubifex, will be at particular risk of metal and metal NP exposure. However, a range of complex transformation processes in the sediment affects NP bioavailability and toxicity as the contamination ages. The objective of this study was to examine bioaccumulation and adverse effects of CuO NPs in T. tubifex compared to dissolved Cu (administered as CuCl2) and the influence of aging of spiked sediment. This was done in a 28-day exposure experiment with T. tubifex incubated in clean sediment or freshly spiked sediment with different concentrations of dissolved Cu (up to 230 μg g−1 dw) or CuO NPs (up to 40 μg g−1 dw). The experiment was repeated with the same sediments after it had been aged for 2 years. To obtain a distinct isotopic signature compared to background Cu, both Cu forms were based on the stable isotope 65Cu (&gt;99%). The 28-day exposure to sediment-associated dissolved 65Cu and 65CuO NPs resulted in a clear concentration-dependent increase in the T. tubifex65Cu body burden. However, despite the elevated 65Cu body burdens in exposed worms, limited adverse effects were observed in either of the two experiments (e.g., above 80% survival in all treatments, low or no effects on the growth rate, feeding rate, and reproduction). Organisms exposed to aged sediments had lower body burdens of 65Cu than those exposed to freshly spiked sediments and we suggest that aging decreases the bioavailability of both 65Cu forms. In this study, the use of a stable isotope made it possible to use environmentally realistic Cu concentrations and, at the same time, differentiate between newly accumulated 65Cu and background Cu in experimental samples despite the high background Cu concentrations in sediment and T. tubifex tissue. Realistic exposure concentrations and aging of NPs should preferably be included in future studies to increase environmental realism to accurately predict the environmental risk of metal NPs

Bisphenol A and Bisphenol S Induce Endocrine and Chromosomal Alterations in Brown Trout

Bisphenol A is a widely used compound found in large amount of consumer products. As concerns have been raised about its toxicological and public health effect, the use of alternatives to bisphenol A are now increasing. Bisphenol S is one of the analogues being used as a replacement for bisphenol A despite the fact that little is known about the effects of bisphenol S on living organisms. In this study, we investigated the potential endocrine and genotoxic effects of bisphenol A and bisphenol S in juvenile brown trout (Salmo trutta). The fish were exposed to the compounds for either 2 weeks or 8 weeks via sustained-release cholesterol implants containing doses of 2 mg/kg fish or 20 mg/kg fish of the substances. The effects on the thyroid hormone levels and the estrogenic disrupting marker vitellogenin were evaluated, along with the genotoxic markers micronucleated cells and erythrocyte nuclear abnormalities. An increase in plasma vitellogenin was observed in fish exposed to the high dose of bisphenol A for 2 weeks. At this experimental time the level of the thyroid hormone triiodothyronine (T3) in plasma was elevated after bisphenol S exposure at the high concentration, and paralleled by an increase of micronucleated cells. Moreover, bisphenol A induced an increase of micronuclei frequency in fish erythrocytes after the exposure at the lowest dose tested. Taken together the results indicate that both bisphenol A and its alternative bisphenol S cause endocrine disrupting and genotoxic effects in brown trout, although suggesting two different mechanisms of damage underlying bisphenol A and bisphenol S activity