Combined effect of lead exposure and allostatic load on cardiovascular disease mortality-a preliminary study

This study explores the combined effect of lead (Pb) exposure and an index of chronic physiological stress on cardiovascular disease mortality using data from the National Health and Nutrition Examination Survey (NHANES) 1999-2008 linked to 1999-2014 National Death Index data. Chronic physiological stress was measured using the allostatic load (AL) index, which was formed by analyzing markers from the cardiovascular, inflammatory, and metabolic systems, with Pb levels, assessed using blood lead levels (BLL). The dataset was analyzed with statistical techniques to explore (a) the relationship between Pb exposure and AL, and (b) the combined role of Pb and AL on cardiovascular disease mortality. Results indicated that AL was more elevated in those with BLLs above the 50th percentile in the US population and that those with elevated AL were more likely to have high BLL. Finally, the interaction of AL and BLL significantly increased the likelihood of cardiovascular disease mortality. These findings highlight the need for considering the totality of exposures experienced by populations to build holistic programs to prevent Pb exposure and reduce stressors to promote optimal health outcomes and reduce cardiovascular mortality risk

Environmental Research and Public Health Communication Pathogens in Ornamental Waters: A Pilot Study

Abstract: In parks, ornamental waters of easy access and populated with animals are quite attractive to children and yet might hide threats to human health. The present work focuses on the microbiota of the ornamental waters of a Lisboa park, characterized during 2015. The results show a dynamic microbiota integrating human pathogens such as Klebsiella pneumoniae, Aeromonas spp. and Enterobacter spp., and also antibiotic resistant bacteria. K. pneumoniae and Aeromonas spp. were present as planktonic and biofilm organized bacteria. In vitro K. pneumoniae and Aeromonas spp. showed an enhanced ability to assemble biofilm at 25˝C than at 37˝C. Bacteria recovered from biofilm samples showed an increased antibiotic resistance compared to the respective planktonic counterparts

Categorization of nearshore sampling data using oil slick trajectory predictions

Oil Spill Chemicals (OSCs) represent a risk to the environment and human health, especially in nearshore environments used for recreational purposes. Importantly, the starting point for human health risk assessment is to define the concentration of OSCs at nearshore locations. The objective of this study was to evaluate nearshore sampling data of OSC concentrations in different environmental matrices within time-space specific categories. The categories correspond to OSC concentration values for samples collected prior to nearshore oiling, post nearshore oiling and at no time impacted by oil as predicted by historic oil spill trajectories generated by an Oil Spill Trajectory Model. In general, concentration values for the post category were higher than prior which were higher than unimpacted. Results show differences in PAH concentration patterns within each matrix and for each category. Concentration frequency distributions for most chemicals in each category were log-normally distributed. [Display omitted] •Toxic Oil Spill Chemicals (OSCs) represent a risk to human health.•OSC distributions were categorized in a spatial and temporal context.•Two spatial-temporal categories had statistically higher mean concentrations.•Results show differences in concentration patterns for each category.•Concentration frequency distributions for most OSCs were log-normally distributed

Review of methods to determine hand surface area of children less than six years old: a case study

Various methods exist to determine the surface area of hands. The consistency of these methods is essential given that risk assessments utilize hand surface area (HSA) to quantify exposure to environmental contaminants. HSA is also utilized in the clinical setting to estimate size of burns, and to determine specific treatments and medication dosages. A reliable method of surface area measurement is important to guide these decisions, especially in children who are vulnerable to environmental contaminants and medication side effects. Despite this, fewer HSA-determining studies have been performed for children compared to adults. In this study, 122 children completed hand tracings, and the tracings were digitized using an ImageJ program to determine HSA. Six previously published methods of determining HSA were utilized based on the child's height, weight, and length and width of hand. Children were analyzed by age group including 0-2, 3-4, and 5-6 years. The HSA measurements determined by five of the six methods were statistically different from HSA determined using direct hand tracings/Image J methodology (p < 0.001). The single remaining study that did not differ significantly from the hand tracing method provided a uniform hand to total body surface area (TBSA) ratio for children of all ages. Based on these results, we propose a novel age-group-specific ratio utilizing the HSA results from hand tracings and TBSA calculations. The percentages of TBSA that reflect HSA for children aged 0-2, 3-4 and 5-6 years were 0.91%, 0.90% and 0.87%, respectively. These percentages should be considered for use in risk assessments and the clinical setting to guide treatment and prognosis

Relative Pesticide and Exposure Route Contribution to Aggregate and Cumulative Dose in Young Farmworker Children

The Child-Specific Aggregate Cumulative Human Exposure and Dose (CACHED) framework integrates micro-level activity time series with mechanistic exposure equations, environmental concentration distributions, and physiologically-based pharmacokinetic components to estimate exposure for multiple routes and chemicals. CACHED was utilized to quantify cumulative and aggregate exposure and dose estimates for a population of young farmworker children and to evaluate the model for chlorpyrifos and diazinon. Micro-activities of farmworker children collected concurrently with residential measurements of pesticides were used in the CACHED framework to simulate 115,000 exposure scenarios and quantify cumulative and aggregate exposure and dose estimates. Modeled metabolite urine concentrations were not statistically different than concentrations measured in the urine of children, indicating that CACHED can provide realistic biomarker estimates. Analysis of the relative contribution of exposure route and pesticide indicates that in general, chlorpyrifos non-dietary ingestion exposure accounts for the largest dose, confirming the importance of the micro-activity approach. The risk metrics computed from the 115,000 simulations, indicate that greater than 95% of these scenarios might pose a risk to children’s health from aggregate chlorpyrifos exposure. The variability observed in the route and pesticide contributions to urine biomarker levels demonstrate the importance of accounting for aggregate and cumulative exposure in establishing pesticide residue tolerances in food

PAH depletion in weathered oil slicks estimated from modeled age-at-sea during the Deepwater Horizon oil spill

During time-periods oil slicks are in the marine environment (age-at-sea), weathering causes significant changes in composition and mass loss (depletion) of oil spill chemicals including the more toxic polycyclic aromatic hydrocarbons (PAHs). The goal of this study was to estimate the age-at-sea of weathered oil slicks using the oil spill module of the Connectivity Modeling System and to use this age to interpret PAH concentration measurements. Percent depletion (PD) for each measurement was computed as the percentage difference between the original and measured PAH concentration in the crude oil and weathered oil slicks, normalized upon the mass losses relative to hopane. Mean PD increased with estimated age-at-sea for all PAHs. Less PD was observed for alkylated than for parent PAHs, likely due to decreasing vapor pressure with increasing degree of alkylation. We conclude that estimated age-at-sea can be used to explain PAH depletion in weathered oil slicks. We propose PAH vapor pressure can be coupled with the model to expand capacity for predicting concentration distributions of individual parent and alkylated PAHs in weathered oil along the coastline. This new module will advance the science supporting oil spill response by providing more certain estimates of health risks from oil spills.[Display omitted]•Evaluated relationship between age-at-sea and PAH depletion.•PAH depletion increased with estimated age-at-sea.•PAH vapor pressure decreased with increasing alkylation.•A new module to predict PAH concentration distributions is recommended.•Improved oil spill response through better estimates of health risks

Estimating Health Risks to Children Associated with Recreational Play on Oil Spill-Contaminated Beaches

The human health impact from exposure to contaminated shorelines following an oil spill event has been investigated to some extent. However, the health risks to children have largely been characterized through the use of surveys and extrapolation from adult health outcomes. There is limited information on children&rsquo;s behaviors during beach play requiring assumptions made based on observations from play activities in home settings. The Beach Exposure and Child Health Study (BEACHES) quantified specific beach activities that can be used to inform human health risk assessments of children playing on beaches impacted by oil spills. The results of this study characterize children&rsquo;s risk of cancer from exposure to oil spill chemicals by incorporating exposure-related information collected from the BEACHES study and by assuming oral, dermal, and inhalation exposure routes. Point risk estimates are compared with a previous, similar study that applied default exposure parameter values obtained from the published literature. The point risk estimates informed by BEACHES data are one order of magnitude lower compared with the previous risk assessment, with dermal exposures the overall risk driver in both. Additional Monte Carlo simulations evaluating the BEACHES data provide ranges of health risks with the highest estimates associated with dermal and oral exposure routes

Children’s Abrasions in Recreational Beach Areas and a Review of Possible Wound Infections

The Beach Exposure and Child Health Study (BEACHES) quantified the behavior of children at recreational beach areas to evaluate how various behaviors might affect their exposure to environmental contaminants such as bacteria and chemicals. Due to limited information in the study about abrasions, we conducted a literature review to examine how marine bacteria cause infections in open wounds. The literature review revealed possible adverse health effects from the bacteriumVibrio vulnificusdue to its increasing prevalence and the severity of infection. We used data from the BEACHES study to review children’s behavior and their susceptibility to abrasions. Children six years of age and younger were evaluated before and after 1 h of play for open or healing abrasions at two beaches in Miami-Dade County, Florida (Crandon and Haulover), and two beaches in Galveston County, Texas (Stewart and Seawall). The children were videotaped to monitor their activities and to determine the behavior that would increase their susceptibility to obtaining abrasions. Overall, 58.2% of the children had at least one existing abrasion before playing at the beach, while 8.2% of the children acquired a new abrasion during their time at the beach. Children who acquired new abrasions most often played in the sea water, with new abrasions most frequently occurring on exposed skin surfaces such as the knees. Proper wound care before and after visiting the beach should be encouraged to minimize the risk of bacterial infection, especially considering the possible detrimental impacts that can be caused by some bacterial pathogens through wound exposures

Use of chemical concentration changes in coastal sediments to compute oil exposure dates

Oil spills can result in changes in chemical contaminant concentrations along coastlines. When concentrations are measured along the Gulf of Mexico over time, this information can be used to evaluate oil spill shoreline exposure dates. The objective of this research was to identify more accurate oil exposure dates based on oil spill chemical concentrations changes (CCC) within sediments in coastal zones after oil spills. The results could be used to help improve oil transport models and to improve estimates of oil landings within the nearshore. The CCC method was based on separating the target coastal zone into segments and then documenting the timing of large increases in concentration for specific oil spill chemicals (OSCs) within each segment. The dataset from the Deepwater Horizon (DWH) oil spill was used to illustrate the application of the method. Some differences in exposure dates were observed between the CCC method and between oil spill trajectories. Differences may have been caused by mixing at the freshwater and sea water interface, nearshore circulation features, and the possible influence of submerged oil that is unaccounted for by oil spill trajectories. Overall, this research highlights the benefit of using an integrated approach to confirm the timing of shoreline exposure. [Display omitted] •A new method is developed to compute oil exposure dates and regions.•Dates and regions were computed from concentrations of shoreline sediments.•Differences were observed against exposure dates predicted by oil spill trajectories.•Nearshore circulation features appear to account for some differences.•Cyclones also appear to influence exposure dates. Shoreline oil exposure dates were computed from concentrations of shoreline sediments measured during an oil spill