Changes in Lumbriculus variegatus metabolites under hypoxic exposure to benzo(a)pyrene,chlorpyrifos and pentachlorophenol: Consequences on biotransformation

The regulation of endogenous metabolites is still not fully understood in aquatic invertebrates exposed concurrently to toxicants and hypoxia. Despite the prevalence of hypoxia in the aquatic environment, toxicity estimations seldom account for multiple stressors thereby differing from natural conditions. In this study, we examined the influence of hypoxia (<30% O₂) on contaminant uptake and the composition of intracellular metabolites in Lumbriculus variegatus exposed to benzo(a)pyrene (B(a)P, 3 μg L⁻¹), chlorpyrifos (CPF, 100 μg L⁻¹) or pentachlorophenol (PCP, 100 μg L⁻¹). Tissue extracts of worms were analyzed for 123 metabolites by gas chromatography–mass spectrometry and metabolite levels were then related to treatments and exposure time. Hypoxia markedly increased the accumulation of B(a)P and CPF, which underlines the significance of oxygen in chemical uptake. The oxygen effect on PCP uptake was less pronounced. Succinate and glycerol-3-phosphate increased significantly (p < 0.0001) following hypoxic treatment, whereas sugars, cysteine, and cholesterol were effectively repressed. The buildup of succinate coupled with the corresponding decline in intracellular 2-oxo- and 2-hydroxy glutaric acid is indicative of an active hypoxia inducible factor mechanism. Glutamate, and TCA cycle intermediates (fumarate, and malate) were disturbed and evident in their marked suppression in worms exposed concurrently to hypoxia and PCP. Clearly, hypoxia was the dominant stressor for individuals exposed to B(a)P or CPF, but to a lesser extent upon PCP treatment. And since oxygen deprivation promotes the accumulation of different toxicants, there may be consequences on species composition of metabolites in natural conditions.     

Effect of combustion condition on cytotoxic and inflammatory activity of residential wood combustion particles

Residential heating is an important local source of fine particles and may cause significant exposure and health effects in populations. We investigated the cytotoxic and inflammatory activity of particulate emissions from normal (NC) and smouldering (SC) combustion in one masonry heater. The PM_1–0.2 and PM_0.2 samples were collected from the dilution tunnel with a high-volume cascade impactor (HVCI). Mouse RAW 264.7 macrophages were exposed to the PM-samples for 24 h. Inflammatory mediators, (IL-6, TNFα and MIP-2), and cytotoxicity (MTT-test), were measured. Furthermore, apoptosis and cell cycle of macrophages were analyzed. The HVCI particulate samples were characterized for ions, elements and PAH compounds. Assays of elemental and organic carbon were conducted from parallel low volume samples. All the samples displayed mostly dose-dependent inflammatory and cytotoxic activity. SC samples were more potent than NC samples at inducing cytotoxicity and MIP-2 production, while the order of potency was reversed in TNFα production. SC-PM_1–0.2 sample was a significantly more potent inducer of apoptosis than the respective NC sample. After adjustment for the relative toxicity with emission factor (mg MJ^?1), the SC-PM emissions had clearly higher inflammatory and cytotoxic potential than the NC-PM emissions. Thus, operational practice in batch burning of wood and the resultant combustion condition clearly affect the toxic potential of particulate emissions.     

17α-Ethinylestradiol in Lakes of Hanoi and its effect on seed germination

Abstract

The lakes of Hanoi are important water resources for urban agriculture. The concentrations of 17α-ethinylestradiol in the water of three major lakes were found to range from 0.1 to 9.1?ng/L, peaking during the rainy season. Effects at levels from 1?ng/L to 1?µg/L on the germination of mung bean (Vigna radiata) and bok choy (Brassica rapa) were studied. Soaking the seeds in solutions containing 17α-ethinylestradiol at 10?ng/L and higher increased the germination rate of mung bean but not of bok choy. For the latter, irrigation after sowing with solutions containing 17α-ethinylestradiol at 10?ng/L and higher accelerated germination.

Abbreviations: MNRE: Ministry of Natural Resources and Environment; PE₆₀: Population equivalent; USGS: U.S. Geological Survey; SPE: Solid phase extraction; EDTA: Disodium ethylenediaminetetraacetate; HPLC: High performance liquid chromatography; ELISA: Enzyme-linked immunosorbent assay; DOM: Dissolved organic matter; EEQ: Estradiol equivalent     

Emergent publics and affects in environmental governance

Drawing on the wide social scientific literature on emotions and affects, we highlight the value and potential contribution of the affect theory for understanding public engagement in environmental policy and planning. We suggest that such theorization complements political ontologies that envision concerned publics to arise as citizens are attached to objects and other beings in their everyday life. Focus on emotions and affects enables in-depth exploration of the corporeality of these attachments, increasing understanding about how affected publics get driven for action and how new sensibilities and horizons for action are created. Based on the discussion of affect theory and case examples, we argue that emotions and affects should be treated as crucial carriers of knowledge about transformation of political subjects and their concerns. They also direct analytic gaze beyond public participation procedures and encourage the development of novel, more inclusive settings for public engagement.