纳米二氧化硅对秀丽线虫的毒性作用研究

为探讨二氧化硅纳米颗粒(SiNP)的毒性作用.以微米SiO2和空白做对照,将尺寸为20和60 nm的SiNP分别以0.2,1.0和5.0 g·L-13个浓度对模式生物秀丽隐杆线虫进行染毒.通过第一代和第二代线虫体长、身体弯曲频率、头部摆动频率以及第一代线虫后代数目、世代时间等发育、运动和生殖的相关评价指标,对SiNP毒...     

Risk to humans of consuming metals in anchovy (<Emphasis Type="Italic">Coilia</Emphasis> sp.) from the Yangtze River Delta

Concentrations of metals were determined in four species of anchovy (Coilia sp.) from the Yangtze River, Taihu Lake, and Hongze Lake in Jiangsu Province, China. Concentrations of Cr in anchovy fish muscle ranged from 2.6 × 10⁻² to 5.0 mg/kg ww, and Coilia nasus taihuensis in Jiaoshan, Taihu Lake contained the highest concentrations of Cr, which was almost 111-fold higher than the mean value at other locations. Concentrations of Pb ranged from 1.5 × 10⁻² to 1.3 × 10⁻¹ mg/kg ww. Comparisons of concentrations of lead (Pb) among the four species indicated that anadromous species contained higher concentrations of Pb than did freshwater species. However, concentrations of Pb in C. nasus from the Nanjing and Haimen locations in the Yangtze River were not significant higher than those of two freshwater species: C. nasus taihuensis from Taihu Lake and C. brachygnathus from Hongze Lake (Duncan’s test, α = 0.05). While concentrations of Cd and Zn ranged from 7.0 × 10⁻⁴ to 3.6 × 10⁻³ mg/kg ww and 3.4 to 4.8 mg/kg ww, respectively, there were no significant differences in concentrations among the eight locations. The only concentration of the metals studied that exceeded the Chinese National Standard was Cr in Coilia from Jiaoshan, Taihu Lake, which was 2.5-fold higher than the standard. These results indicate that people who consume the genus Coilia are not at risk due to concentrations of metals, except Cr in C. nasus taihuensis from Jiaoshan in Taihu Lake. Concentrations of all of the metals studied except for Cr were similar to or less than those of metals in most other areas in the world.     

The relationship between speeding behaviour (as measured by violation convictions) and crash involvement

While it seems rational to assume that crash involvement risk and outcome are influenced by the way one drives, nevertheless there is continuing controversy over the validity of certain categories of traffic law infractions as true measures of such behavior. Specifically, does the accumulation of tickets for speeding identify drivers as high risk for becoming culpably involved in speed-related crashes? Further, does a proclivity for exhibiting speeding behavior in the presence of police translate into a greater risk for involvement in high-severity collisions?The research reported in this paper attempted to address these issues. Several years of crash and conviction data were utilized to examine

• 1.(a) the risk of culpable crash involvement by severity of outcome during a 2-year period following 3 years of conviction record,
• 2.(b) the degree to which an increasing level of speeding convictions per driver relates to an increasing propensity for speed to be a factor in drivers' crash involvements.

The results of the research identified a clear distinction between the conviction categories of “exceeding the speed limit” and “excessive speed” in terms of these accident-violation relationships.     

Seeking to improve care for young patients: Development of tools to support the implementation of the CDC Pediatric mTBI Guideline

IntroductionThe Centers for Disease Control and Prevention (CDC) Pediatric Mild Traumatic Brain Injury (mTBI) Guideline was created to help standardize diagnosis, prognosis, and management and treatment of pediatric mTBI. This paper describes the process CDC used to develop educational tools, and a dissemination and implementation strategy, in support of the CDC Pediatric mTBI Guideline.MethodsTwo qualitative data collection projects with healthcare providers who care for pediatric patients were conducted. In-depth interviews were used in both projects. Project One examined healthcare providers' guideline use and dissemination preferences. Project Two assessed perceptions of the CDC Pediatric mTBI Guideline educational tools.ResultsProject One brought to light four key areas related to Guideline usage and dissemination preferences, specifically a need for: (1) partnership with professional medical societies; (2) integration into electronic health records, mobile apps, and websites; (3) development of continuing medical education (CME) opportunities; and (4) dissemination through healthcare system leadership. In Project Two, healthcare providers reported that the CDC Pediatric mTBI Guideline educational tools were well-organized, clear and easy to navigate, and informative. Healthcare providers also requested more information on the Guideline methodology.DiscussionAssessment of pediatric healthcare providers' current use of clinical guidelines and preferences for educational tools yielded important insights that helped inform CDC's dissemination and implementation strategy for the Pediatric mTBI Guideline.Practical applicationsThe findings from these data collection projects can also inform other guideline implementation and dissemination efforts among healthcare providers.     

Cobalt exposure in relation to cardiovascular disease in the United States general population

Environmental Science and Pollution Research - Cobalt exposure has adverse health effects on the cardiovascular system in occupational and laboratory studies, but these effects have not been...     

Human dietary intake of organohalogen contaminants at e-waste recycling sites in Eastern China

This study reports concentrations and human dietary intake of hexabromocyclododecanes (HBCDs), polychlorinated biphenyls (PCBs) as well as selected “novel” brominated flame retardants (NBFRs) and organochlorine pesticides, in ten staple food categories. Samples were sourced from areas in Taizhou City, eastern China, where rudimentary recycling and disposal of e-waste is commonplace, as well as from nearby non-e-waste impacted control areas. In most instances, concentrations in foods from e-waste recycling areas exceeded those from control locations. Concentrations of 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) and bis-(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (BEH-TBP) in samples from e-waste sites were 3.09–62.2 ng/g and 0.81–16.3 ng/g lipid weight (lw), respectively; exceeding consistently those in foods acquired from control sites by an order of magnitude in many cases. In contrast, while concentrations of HBCD in some foods from e-waste impacted areas exceed those from control locations; concentrations in pork, shrimp, and duck liver are higher in control samples. This highlights the potential significance of non-e-waste sources of HBCD (e.g. building insulation foam) in our study areas. While concentrations of DDT in all foods examined except pork were higher in e-waste impacted samples than controls; our exposure estimates were well below the provisional tolerable daily intake of 0.01 mg/kg bw/day derived by the Joint FAO/WHO Meeting on Pesticide Residues. Concentrations of ΣPCBs resulted in exposures (650 and 2340 ng/kg bw/day for adults and children respectively) that exceed substantially the Minimal Risk Levels (MRLs) for ΣPCBs of 20 ng/kg bw/day derived by the Agency for Toxic Substances & Disease Registry. Moreover, when expressed in terms of dioxin-like toxicity equivalency based on the four dioxin-like PCBs monitored in this study (DL-PCBs) (PCB-105, 118, 156, and 167); concentrations in e-waste impacted foods exceed limits set by the European Union in 6 of the 8 food groups studied and result in dietary exposures for children (10.2 pg TEQ/kg bw/day) that exceed the WHO tolerable daily intake of 1–4 pg TEQ/kg bw/day.     

Prenatal and early-life polychlorinated biphenyl (PCB) levels and behavior in Inuit preschoolers

BackgroundWhereas it is well established that prenatal exposure to polychlorinated biphenyls (PCBs) can disrupt children's behavior, early postnatal exposure has received relatively little attention in environmental epidemiology.ObjectivesTo evaluate prenatal and postnatal exposures to PCB-153, a proxy of total PCB exposure, and their relation to inattention and activity in 5-year-old Inuits from the Cord Blood Monitoring Program.MethodsPrenatal exposure to PCBs was informed by cord plasma PCB-153 levels. We used a validated pharmacokinetic model to estimate monthly infants' levels across the first year of life. Inattention and activity were assessed by coding of video recordings of children undergoing fine motor testing. We used multivariable linear regression to evaluate the association between prenatal and postnatal PCB-153 levels and inattention (n = 97) and activity (n = 98) at 5 years of age.ResultsCord plasma PCB-153 was not associated with inattention and activity. Each interquartile range (IQR) increase in estimated infant PCB-153 levels at 2 months was associated with a 1.02% increase in the duration of inattention (95% CI: 0.04, 2.00). Statistical adjustment for the duration of breastfeeding slightly increased regression coefficients for postnatal level estimates, some of which became statistically significant for inattention (months: 2–4) and activity (months: 2–5).ConclusionsOur study adds to the growing evidence of postnatal windows of development during which children are more susceptible to neurotoxicants like PCBs.     

Pre- and postnatal exposures to pesticides and neurodevelopmental effects in children living in agricultural communities from South-Eastern Spain

BackgroundChildrens exposure to neurotoxic compounds poses a major problem to public health because of their actively developing brain that makes them highly vulnerable. However, limited information is available on neuropsychological effects in children associated with pre- and postnatal exposures to pesticides.ObjectiveTo evaluate the association between current and pre- and postnatal exposures to pesticides and their effects on neurodevelopment in children aged 6–11 years living in agricultural communities from South-Eastern Spain.MethodsAn ambispective study was conducted on 305 children aged 6–11 years randomly selected from public schools of the study area. Current exposure to organophosphate pesticides was assessed measuring children's urinary levels of dialkylphosphates (DAPs). Both prenatal and postnatal residential exposure to pesticides was estimated by developing a geographical information system (GIS) technology-based index that integrated distance-weighted measure of agricultural surface, time-series of crop areas per municipality and year, and land-use maps. Neuropsychological performance was evaluated with the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV). The association of pre- and postnatal and current pesticide exposure with WISC-IV scale scores was assessed using multivariate linear regression models and generalized estimating equation (GEE) models, respectively.ResultsGreater urinary DAP levels were associated with a poorer performance on intelligence quotient and verbal comprehension domain, with effects being more prominent in boys than in girls. The influence of an increase in 10 ha per year in crop surface around the child's residence during the postnatal period was associated with decreased intelligence quotient, processing speed and verbal comprehension scores. As regards prenatal exposure to pesticides, a poor processing speed performance was observed. These effects were also more prominent in boys than in girls.ConclusionsOur results suggest that postnatal exposure to pesticides can negatively affect children's neuropsychological performance. Prenatal exposure was weakly associated to neurodevelopment impairment.     

Gene-gene and gene-environment interactions on risk of male infertility: Focus on the metabolites

Infertility affects about 17% couples, and males contribute to half of the cases. Compared with independent effects of genetic and environmental factors, interactions between them help in the understanding of the susceptibility to male infertility. Thus, we genotyped 25 polymorphisms, measured 16 urinary chemical concentrations and explored interactions between gene-gene and gene-environment in 1039 Han Chinese using metabolomic analysis. We first observed that GSTT1 might interact with GSTM1 (P_inter = 6.33 × 10^− 8). Furthermore, an interaction between GSTM1 and 4-n-octylphenol (4-n-OP) was identified (P_inter = 7.00 × 10^− 3), as well as a 2-order interaction among GSTT1, GSTM1 and 4-n-OP (P_inter = 0.04). Subjects with GSTT1-present and GSTM1-null genotypes were susceptible to male infertility when exposed to 4-n-OP (OR = 14.05, 95% CI = 4.78–60.20, P = 2.34 × 10^− 5). Most metabolites identified were involved in the tricarboxylic acid cycle. In conclusion, it is a novel study of the interaction on male infertility from the aspect of metabolomics.