Aqueous solutions of gamma-hexachlorocyclohexane (Lindane) were photolyzed (lambda=254 nm) under a variety of solution conditions. The initial concentrations of hydrogen peroxide (H(2)O(2)) and Lindane varied from 0 to 20 mM and 0.21 to 0.22 microM, respectively, the pH ranged from 3 to 11, and several concentration ratios of Suwannee River humic acid and fulvic acid were dissolved in the irradiated solutions. Lindane rapidly reacted, and the maximum reaction rate constant (9.7 x 10(-3) s(-1)) was observed at pH 7 and initial [H(2)O(2)]=1 mM. Thus, 90% of the Lindane is destroyed in approximately 4 min under these conditions. In addition, within 15 min, all chlorine atoms were converted to chloride ion, indicating that chlorinated organic by-products do not accumulate. The reactor was characterized by measuring the photon flux (7.04 x 10(-6) E s(-1)) and the cumulative production of *OH during irradiation. The cumulative *OH production during irradiation was fastest at an initial [H(2)O(2)]=5 mM (k=0.77 micro M s(-1)).
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http://dx.doi.org/10.1016/j.chemosphere.2008.04.080 | DOI Listing |
Sci Total Environ
January 2025
Centro de Genómica, Ecología y Medio Ambiente (GEMA), Universidad Mayor, Campus Huechuraba, Santiago, Chile; Institute of Environment, Florida International University, University Park, Miami, FL 33199, USA; Data Observatory Foundation, Santiago, Chile. Electronic address:
Semi-volatile organic compounds (SVOCs) are widely distributed across the globe, including polar regions. This study investigates the distribution and bioconcentration of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) in soils and Colobanthus quitensis, while also estimating potential emission sources. Results indicated high concentrations of PAHs in soils and plants from the Sub-Antarctic region, while OCPs and PCBs were more prevalent in the Antarctic region, with higher contaminant concentrations found in soils than in plant tissues.
View Article and Find Full Text PDFEcotoxicology
January 2025
Unidad Académica Mazatlán, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Mazatlán, Sinaloa, México.
Monitoring the dynamics of contaminants in ecosystems helps understand their potential effects. Seabirds have been used as biomonitors of marine ecosystems for this purpose. However, exposure and vulnerability to pollutants are understudied in tropical species, and the relationships between various pollutants and the trophic ecology of seabirds are poorly understood.
View Article and Find Full Text PDFImmunopharmacol Immunotoxicol
February 2025
Nursing Department, College of Nursing and Health Sciences, Jazan University, Jazan, Saudi Arabia.
Background: One of the common findings in systemic sclerosis (SSc) patients has been long-term exposure to environmental toxins such as pesticides. However, the data available shows an equivocal association between pesticide exposure and autoimmunity in SSc.
Methods: We investigated the levels of organochlorine pesticides (OCPs) in blood of 20 SSc patients and 17 healthy controls, and also studied their effect on T lymphocytes and their functional responses.
Environ Sci Technol
January 2025
Environment and Climate Change Canada, Ecotoxicology and Wildlife Health Division, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.
Contaminant monitoring programs use wild bird eggs, but determining whether measured concentrations elicit adverse effects relies on extrapolation from toxicity studies with avian model species. Here, we directly evaluated the relationships between whole embryo contaminant concentrations and mRNA expression in liver tissue of the double-crested cormorant (). Eggs collected from three North American sites (one from Lake Erie and two from the Salish Sea) were artificially incubated until pipping.
View Article and Find Full Text PDFToxicol Res (Camb)
December 2024
Bee Research Department, Plant Protection Research Institute, Agricultural Research Center, Dokki 12619, Giza, EGYPT.
A growing trend in understanding human health involves looking at the bigger picture by examining all potential environmental exposures that may cause health risks, with a particular focus on dietary intake of anthropogenic chemicals. This study investigated the presence of pesticide residues in honey and pollen samples collected randomly from ten locations in four agricultural governorates during the spring season of 2023 in the Nile Delta, Egypt. A QuEChERS extraction was employed for sample preparation before GC-MS analysis for pesticide residues.
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