2,106 research outputs found
ESTIMATING CHILDREN’S HEALTH RISKS FROM RECREATIONAL BEACH PLAY FOLLOWING AN OIL SPILL
Environmental contamination from marine oil spills can have damaging impacts on ecosystems and human health. In 2010, an explosion of the Deepwater Horizon (DWH) oil drilling platform resulted in approximately 1,728 km of shoreline oiling. Existing research characterizes health risk from exposure to oil spill chemicals (OSCs) for adults; however, data on impacts to child health are limited. One objective of the Beach Exposure And Child HEalth Study (BEACHES), funded by the Gulf of Mexico Research Initiative, is to estimate health risks to children between walking and six years of age from exposure to OSCs in a post-oil spill scenario during normal recreational beach activity. The National Research Council (NRC) risk assessment framework was adapted to account for child behavior patterns. Child macro- and micro-activity data were gathered from 391 parent surveys and recorded observations of beach play from 119 children from two beaches each in Miami, Florida and Galveston, Texas. Chemical concentration and distribution data for various OSCs (such as alkanes, polycyclic aromatic hydrocarbons, metals, and dispersants) were aggregated from existing literature and combined with micro-activity data to generate cancer and non-cancer risk ranges for oral (non-dietary), dermal, and inhalation exposures. Each input variable in the risk assessment framework was evaluated to determine which variable(s) have the most significant impact on overall risk estimates. A Monte Carlo analysis (MCA) was conducted to address uncertainty and variability of both the assumed and observed datasets. Finally, a sensitivity analysis was performed to investigate the different distributional assumptions for each model input. These analyses revealed gaps in current research to provide useful information in guiding local, regional, and national public health agencies regarding monitoring of hazards, beach advisories and closures, and media response in the event of a chemical disaster event
Tris(1,3-dichloro-2-propyl) phosphate disrupts dorsoventral patterning in zebrafish embryos.
Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) is a high-production volume organophosphate flame retardant widely used within the United States. Within zebrafish, initiation of TDCIPP exposure at 0.75 h post-fertilization (hpf) results in genome-wide alterations in methylation during cleavage (2 hpf) as well as epiboly delay or arrest (at higher concentrations) during late-blastula and early-gastrula (4-6 hpf). To determine whether these TDCIPP-induced effects were associated with impacts on the transcriptome, embryos were exposed to vehicle (0.1% DMSO) or 2 µM TDCIPP from 0.75 hpf to 6 hpf, and total RNA was extracted from triplicate embryo pools per treatment and hybridized onto duplicate Affymetrix Zebrafish Gene 1.0 ST Arrays per RNA sample. Based on transcriptome-wide profiling, TDCIPP resulted in a significant impact on biological processes involved in dorsoventral patterning and bone morphogenetic protein (BMP) signaling. Consistent with these responses, TDCIPP exposure also resulted in strongly dorsalized embryos by 24 hpf-a phenotype that mimicked the effects of dorsomorphin, a potent and selective BMP inhibitor. Moreover, the majority of dorsalized embryos were preceded by epiboly arrest at 6 hpf. Our microarray data also revealed that the expression of sizzled (szl)-a gene encoding a secreted Frizzled-related protein that limits BMP signaling-was significantly decreased by nearly 4-fold at 6 hpf. Therefore, we used a splice-blocking morpholino to test the hypothesis that knockdown of szl phenocopies TDCIPP-induced delays in epiboly progression. Interestingly, contrary to our hypothesis, injection of szl MOs did not affect epiboly progression but, similar to chordin (chd) morphants, resulted in mildly ventralized embryos by 24 hpf. Overall, our findings suggest that TDCIPP-induced epiboly delay may not be driven by decreased szl expression, and that TDCIPP-induced dorsalization may-similar to dorsomorphin-be due to interference with BMP signaling during early zebrafish development
1-Acetyl-2-r,6-c-bis(4-chlorophenyl)-3-methyl-1,2,5,6-tetrahydropyridin-4-yl acetate
In the title compound, C22H21Cl2NO3, the pyridine ring adopts a half-chair conformation and the 4-chlorophenyl groups occupy axial positions. The 4-chlorophenyl groups are almost perpendicular to the plane of the tetrahydropyridine ring forming dihedral angles 84.62 (6) and 85.55 (5)°; the dihedral angle between the two 4-chlorophenyl rings is 12.16 (4)°. The crystal structure is stabilized by intermolecular C—H⋯O interactions
2-(2-Methylnaphtho[2,1-b]furan-1-yl)acetic acid
In the title molecule, C15H12O3, the two six-membered and one five-membered fused-ring system is almost planar and the CH2C(=O)OH residue is essentially orthogonal to it. In the crystal structure, centrosymmetric dimers are formed via the carboxylic acid {⋯O=C—O—H}2 synthon
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