Population-level Exposure Research Articles

Incorporating exposure information into the toxicological prioritization index decision support framework

The Toxicological Prioritization Index (ToxPi) decision support framework was previously developed to facilitate incorporation of diverse data to prioritize chemicals based on potential hazard. This ToxPi index was demonstrated by considering results of bioprofiling related to potential for endocrine disruption. However, exposure information is required along with hazard information to prioritize chemicals for further testing. The goal of this analysis is to demonstrate the utility of the ToxPi framework for incorporating exposure information to rank chemicals and improve understanding of key exposure surrogates. The ToxPi tool was applied to common exposure surrogates (i.e., fate parameters, manufacturing volume, and occurrence measurements) and the relationship between resulting rankings and higher-tiered exposure estimates was investigated. As information more directly relevant to human exposure potential is incorporated, relative rank of chemicals changes. Binned ToxPi results are shown to be consistent with chemical priorities based on crude measures of population-level exposure for a limited set of chemicals. However, these bins are not predictive of higher tiered estimates of exposure such as those developed for pesticide registration. Although rankings based on exposure surrogates are used in a variety of contexts, analysis of the relevance of these tools is challenging. The ToxPi framework can be used to gain insight into the factors driving these rankings and aid identification of key exposure metrics. Additional exposure data is required to build confidence in exposure-based chemical prioritization.

Estimating health related costs and savings from balcony acoustic design for road traffic noise

A multi-faceted study is conducted with the objective of estimating the potential fiscal savings in annoyance and sleep disturbance related health costs due to providing improved building acoustic design standards. This study uses balcony acoustic treatments in response to road traffic noise as an example. The study area is the State of Queensland in Australia, where regional road traffic noise mapping data is used in conjunction with standard dose–response curves to estimate the population exposure levels. The background and the importance of using the selected road traffic noise indicators are discussed. In order to achieve the objective, correlations between the mapping indicator (LA10(18hour)) and the dose response curve indicators (Lden and Lnight) are established via analysis on a large database of road traffic noise measurement data. The existing noise exposure of the study area is used to estimate the fiscal reductions in health related costs through the application of simple estimations of costs per person per year per degree of annoyance or sleep disturbance. The results demonstrate that balcony acoustic treatments may provide a significant benefit towards reducing the health related costs of road traffic noise in a community.

Evaluating population exposure to N, N-dimethylformamide in a small industrial area accounting for population movement

Population exposure to pollutants is important for studies on the exposure-response relationship. However, it is difficult to evaluate population exposure to non-conventional pollutants due to limited data on concentration levels and the movement patterns of inhabitants. In this study, an air dispersion model was used to simulate N, N-dimethylformamide (DMF) concentrations, as a proxy to monitoring concentrations. A total of 1289 randomly selected household representatives were surveyed to obtain information on movement characteristics. Subsequently, population movement patterns were combined with DMF concentration levels on maps of 100 m×100 m resolution to calculate population exposure. During 2008, the estimated population exposure to DMF ranged from 0.002 to 0.64 mg/m3. The highest level of population exposure to DMF was found in the north and northwest sub-districts of the study area, ranging from 0.42 to 0.64 mg/m3. The population exposure to DMF for different occupational groups indicated that retired people and farmers were vulnerable subpopulations among people highly exposed to DMF. This was mainly because they spent most time at home where the DMF concentration was high. As pollutant concentrations were divided into small grids, we found that exposure levels were substantially impacted by population movement characteristics.

Identification of Sexual Networks Through Molecular Typing of Quinolone-Resistant Neisseria gonorrhoeae in Ontario, Canada

Neisseria gonorrhoeae multi-antigen sequence typing technique demonstrated multiple sexual transmission networks in Ontario, Canada. Isolates with novel sequences had higher odds of originating in Toronto but had no association with heightened population-level quinolone exposure. Neisseria gonorrhoeae multi-antigen sequence typing technique can be a useful tool for investigation of multidrug-resistant N. gonorrhoeae emergence in North America.

The Pollution Levels of PAHs in Chinese Food

PP-30-095 Background/Aims: In the 1980s, many cities of China began to carry out the study of food PAHs. At that time, most work mainly concentrated on the BaP content of vegetable crops. In the 1990s, researchers started to analyze the PAHs in food such as fish, meat, etc. In recent years, it was also reported that the level of daily dietary exposure to PAHs. Methods: The PAHs contents in food of Chinese provinces are as follows: in 2007, through detecting dried fish and meat floss in Fujian, 12 kinds of PAHs were found. In which the content of naphthalene and phenanthrene is relatively large; the study of population exposure levels of Tianjin showed us that dietary and respiratory exposure is the main way which people exposure to PAHs in Tianjin area. Dietary exposure in the daily exposure is 75%. In dietary intake, the biggest contribution is the grain, almost 38.3%. In 2003, the detection of guangdong foshan vegetable samples showed us that the average content of PAHs is 180.0 μg/kg, the PAHs levels of leafy vegetables is higher than fruit and legumes; 2006 in Guiyang, Guizhou Province, through detecting Fried foods, researchers found that there is excessive amount of BaP in some fried dough sticks; Guangxi Zhuang people have the habit of preserving and eating bacon, they marinate meat with high salt dipping and smoked it to make bacon. The PAHs content of such food is higher; Chongqing locals like to use smoked meat and fish ways to preserve food, which will generated PAHs pollution; Shanghai people like Fried food, such as fried fish/meat, fried pasta, fried eggs, and fried peanuts, which increases the risk of exposure to PAHs. Results: The differences of diet in various regions of China led to the pollution of PAHs in food is not the same. Conclusion: In order to reduce pollution of PAHs in food, we suggest to change the traditional diet in some areas, reduce the consumption of fried and barbecue food.

Scenario analysis and noise action planning: Modelling the impact of mitigation measures on population exposure

This paper reports on strategic noise mapping research conducted in Dublin, Ireland. Noise maps are constructed for the day–evening–night-time and night-time periods and levels of population exposure are estimated for the same periods. In methodological terms, the research uses the UK’s calculation of road traffic noise (CRTN) method for calculating noise levels in the study area. This method has been adopted as the interim calculation method by the Irish authorities responsible for meeting the obligations set out in the EU Environmental Noise Directive (END). The research also investigates the usefulness of three noise mitigation measures for ‘acoustical planning’ purposes: traffic reductions, speed reductions and erection of acoustical barriers. The results indicate that levels of population exposure during night-time are extremely high relative to guideline limits set down by the World Health Organisation. In addition, the results highlight the significant role that certain noise mitigation measures can play in good ‘acoustical planning’.

Ongoing RF Research Studies and Latest Findings Where Available, German Cross Sectional Studies, Bavarian Studies, Swiss Study, UK Base Station, etc.

ISEE-0239 Abstract: Whether exposure to mobile telecommunication networks including base stations might negatively affect health and well-being is of public concern. While laboratory studies have illustrated that concern about the exposure may increase symptoms (nocebo effect), some epidemiologic studies using self-reported exposure as an exposure proxy showed an association between exposure to mobile phone base stations and self-reported well-being. Facing these contradictory findings, mainly cross-sectional population-based studies were recently set-up in a variety of countries (e.g., Australia, France, Germany, the Netherlands, Switzerland, UK) using personal or stationary measurements or modified phones to assess exposure and self-reported symptoms as outcome. The objectives were (depending on the study) to identify 1) population exposure levels, 2) factors predicting individual exposure levels and 3) a potential association between exposure and well-being. All studies indicated exposure levels well below the standard limits. Exposure levels were reproducible over one week. The major challenge was the limit of determination of the exposimeters as a large part of the measurements resulted in values below the limit. Individual exposure was determined by exposure to mobile phone base stations, use of cellular and wireless phones. While an association between self-reported exposure, concerns and well-being could sometimes be shown, no dose-response relationship between measured exposure and symptoms was found. However, two of the studies confirmed recent findings that exposure to mobile telecommunication networks might weakly be associated with behavioural problems in youngsters. In conclusion, the nocebo effect described in laboratory studies could be reproduced in epidemiologic studies. Up to now, no consistent association between measured exposure and well-being could be shown across the age groups. Whether the association found between mobile telecommunication networks and behavioural problems might be due to the electromagnetic fields, the use of the mobile phones themselves or bias has to be shown in prospective studies.

A state indicator on regional scale for high-voltage power lines: defining a priority for in situ inspections

An integrated system to evaluate the magnetic field generated by power lines exposure has been developed using a specific simulation model (PLEIA-EMF). This is part of a software toolset, subjected to internal suitability verifications and in-field validations. A state indicator related to each span has been determined using the data extracted from digital cartography, the magnetic field calculated by PLEIA and the number of people living in the nearest buildings. In this way, it is possible to determine eventual criticalities in the considered area, focusing attention on those cases with more considerable exposure levels and involving a higher number of people. A campaign of inspections has been planned using PLEIA simulations. The reliability of stored technical data and the real population exposure levels have been evaluated in critical cases, individuated through the following described methodology. The procedures leading to the indicator determination and the modalities of in situ inspections are here presented.

Disaggregation of nation-wide dynamic population exposure estimates in The Netherlands: Applications of activity-based transport models

Traditional exposure studies that link concentrations with population data do not always take into account the temporal and spatial variations in both concentrations and population density. In this paper we present an integrated model chain for the determination of nation-wide exposure estimates that incorporates temporally and spatially resolved information about people's location and activities (obtained from an activity-based transport model) and about ambient pollutant concentrations (obtained from a dispersion model). To the best of our knowledge, it is the first time that such an integrated exercise was successfully carried out in a fully operational modus for all models under consideration. The evaluation of population level exposure in The Netherlands to NO 2 at different time-periods, locations, for different subpopulations (gender, socio-economic status) and during different activities (residential, work, transport, shopping) is chosen as a case-study to point out the new features of this methodology. Results demonstrate that, by neglecting people's travel behaviour, total average exposure to NO 2 will be underestimated by 4% and hourly exposure results can be underestimated by more than 30%. A more detailed exposure analysis reveals the intra-day variations in exposure estimates and the presence of large exposure differences between different activities (traffic > work > shopping > home) and between subpopulations (men > women, low socio-economic class > high socio-economic class). This kind of exposure analysis, disaggregated by activities or by subpopulations, per time of day, provides useful insight and information for scientific and policy purposes. It demonstrates that policy measures, aimed at reducing the overall (average) exposure concentration of the population may impact in a different way depending on the time of day or the subgroup considered. From a scientific point of view, this new approach can be used to reduce exposure misclassification.

Tobacco use and bladder cancer patterns in three western European countries

Smoking accounts for >50% of bladder cancers (BCs) in men and 30% in women. Our aim is to explore this large discrepancy by contrasting countries with distinct smoking patterns and habits as these might explain sex differences for BC. Temporal patterns in BC incidence rates, lung cancer (LC) death rates, smoking prevalence and cigarette consumption across time by sex were analyzed by calculating annual percent changes (APCs), using joinpoint regression, for Spain (1973-97), Sweden (1958-97) and the UK (1960-97). APCs for overall BC incidence rates were increasing for both sexes, ranging from 1.43% (1.25; 1.60) (British men) to 3.79% (3.15; 4.44) (Spanish men). APCs for overall LC death rates were also increasing in Sweden and Spain, but the UK showed decreasing APCs for LC death rates in men: -0.48% (-0.86; 0.10). Spain showed decreasing APCs for smoking prevalence among men and increasing APCs among women, -1.65% (-1.79; -1.51) and 2.48% (1.97; 3.00), respectively, but no differences by sex were found for the UK and Sweden. Findings indirectly reflected lag-time of minimum 30 years between smoking and onset of BC. The lack of sex differences for APCs of BC across these countries suggests potential contributions of changes in other population exposure levels.

Riesgo para la salud por radiaciones no ionizantes de las redes de energía eléctrica en el Perú

We review most important national and international publication, specially those which has been conducted within the framework of the International Electromagnetic field Project of the World Health Organization, for known the biological and health effects of the electric energy fields. The level of population, residential and occupational exposure were revised in principal Peruvian evaluation of electricity services and system realized since 2002 to 2008 with representative samples which included more than 1400 locations measurement. Exposure evaluation showed that the highest exposure levels in Peru came from 220 kV high voltage power lines, However, in most cases (98%) are below the recommended limits. The risk assessment of non-ionizing radiation from electric power network in Peru shows that the health risk is not significant.

Assessment of average exposure to organochlorine pesticides in southern Togo from water, maize (Zea mays) and cowpea (Vigna unguiculata)

Drinking water, cowpea and maize grains were sampled in some potentially exposed agro-ecological areas in Togo and analysed for their contamination by some common organochlorine pesticides. A total of 19 organochlorine pesticides were investigated in ten subsamples of maize, ten subsamples of cowpea and nine subsamples of drinking water. Analytical methods included solvent extraction of the pesticide residues and their subsequent quantification using gas chromatography-mass spectrometry (GC/MS). Estimated daily intakes (EDIs) of pesticides were also determined. Pesticides residues in drinking water (0.04–0.40 µg l−1) were higher than the maximum residue limit (MRL) (0.03 µg l−1) set by the World Health Organization (WHO). Dieldrin, endrin, heptachlor epoxide and endosulfan levels (13.16–98.79 µg kg−1) in cowpea grains exceeded MRLs applied in France (10–50 µg kg−1). Contaminants’ levels in maize grains (0.53–65.70 µg kg−1) were below the MRLs (20–100 µg kg−1) set by the Food and Agriculture Organization (FAO) and the WHO. EDIs of the tested pesticides ranged from 0.02% to 162.07% of the acceptable daily intakes (ADIs). Population exposure levels of dieldrin and heptachlor epoxide were higher than the FAO/WHO standards. A comprehensive national monitoring programme on organochlorine pesticides should be undertaken to include such other relevant sources like meat, fish, eggs and milk.

Age, Cohort and Perceived Age Discrimination: Using the Life Course to Assess Self-reported Age Discrimination

Self-reported discrimination is linked to diminished well-being, but the processes generating these reports remain poorly understood. Employing the life course perspective, this paper examines the correspondence between expected age preferences for workers and perceived age discrimination among a nationally representative sample of 7,225 working women, followed between 1972-1989. Analyses find that perceived age discrimination is high in the 20s, drops in the 30s and peaks in the 50s. This curvilinear pattern matches external reports of age preferences and is robust to a variety of controls and model specifications. Additionally, the primary driver of perceived age discrimination is age – not cohort or historical period. These findings suggest that perceived age discrimination is a useful indicator of population-level exposure to work-related age discrimination among women.

Can lessons from public health disease surveillance be applied to environmental public health tracking?

Disease surveillance has a century-long tradition in public health, and environmental data have been collected at a national level by the U.S. Environmental Protection Agency for several decades. Recently, the CDC announced an initiative to develop a environmental public health tracking (EPHT) network with "linkage" of existing environmental and chronic disease data. On the basis of experience with established disease surveillance systems, we suggest how a system capable of linking routinely collected disease and exposure data should be developed. The primary operational goal of EPHT has to be the "treatment" of the environment to prevent and/or reduce exposures and minimize population risk for developing chronic diseases. Thus, EPHT should be synonymous with a dynamic process requiring regular system updates to a) incorporate new technologies to improve population-level exposure and disease assessment, b) allow public dissemination of new data that become available, c) allow the policy community to address new and emerging exposures and disease "threads," and d) evaluate the effectiveness of EPHT over some time interval. It will be necessary to weigh the benefits of surveillance against its costs, but the major challenge will be to maintain support for this important new system.

Assessing the Health Impact of Air Pollution, Noise, and Accidents as a Function of Transport Policies

MS8-06 Abstract: Transport is an essential activity of modern society and brings about potential for development as well as adverse health implications. The HEARTS (Health Effects and Risks of Transport Systems) project had the main objective of developing tools for the integrated assessment of urban transport impacts on health. Air pollution, noise, and road accidents (including pedestrian accidents) were considered in an attempt to support the identification, development, and implementation of urban transport policies that minimize the health impacts. The project targeted several potential users such as administrations, policy-makers, departments of traffic, environment, health, land use planning, consultants companies, scientific and research institutions, environmental consultants, environmental impact assessment (EIA), and health impact assessment (HIA) practitioners. HEARTS brought together experts and modelers of traffic-related exposure, policy scenarios, and health with the main objectives of: Developing methodologies to assess the health impact of transport-related factors in the urban environment; Integrating different impacts (noise, accidents, air pollution); and Testing the proposed methodology based on policies and scenarios of 3 European cities: Leicester, Lille, and Florence. The project underlined the importance of considering the complexity of human exposure to air pollutants, noise, and traffic accidents in an integrated manner to predict the health impacts of transport policies. Dynamic geographic models were used for the assessment of transport-related exposures to air pollution and noise at the local scale, whereas population exposure models using a probabilistic simulation framework were used for broader-scale population-level exposure assessment. The dynamic geographic model was applied using a collection of specific models under a geographic information system (GIS) platform. Newly developed accident and pedestrian risk models were also included. Ad hoc survey campaigns and an additional collection of data were conducted. In the case study cities, transport policy options and different scenarios were identified and assessed in terms of their health implications.

Monitoring Environmental Exposures: Now It’s Personal

Most diseases are thought to arise from the combined effects of genes and the environment. While great strides have been made in our understanding of human genetics, the contribution of environmental exposures to disease remains poorly understood. This lack of understanding impedes real progress in identifying genetically susceptible people whose responses to environmental agents are severe or unique relative to the general population. If identified, targeted prevention and treatment strategies might be applied to these groups, with potentially lifesaving results. Without more personal exposure information, however, scientists have a limited ability to identify pollution-susceptibility genes that elevate disease risk. This mismatch between exposure and genetic research slows the identification of environmental factors that—if altered or removed—could even prevent some diseases from occurring in the first place. “Genes aren’t modifiable,” explains Frederica Perera, a professor of environmental health sciences at the Mailman School of Public Health of Columbia University. “So, these environmental components in diet, food, water, and air are the only ones we can act on for disease prevention.” Exposure is, at a core level, the instance of environmental stimuli such as chemicals, infectious agents, diet, and lifestyle factors interacting with the human body. But studying human exposures poses difficult challenges. Scientists studying the effects of chemical pollutants can’t ethically dose people, so they often base their dose–response estimates on animal models. Further, they base their estimates of human exposure on indirect measures taken from a person’s home or work environment, along with assumptions about individual behaviors that influence the risk of coming into contact with a given pollutant. In a typical study, epidemiologists might use census figures, questionnaires, and general environmental monitoring data (such as samples of water from a household tap or soil in a schoolyard) to estimate how much of a given chemical an individual has come into contact with, and for how long. But while these studies approximate population-level exposures, they provide little information about real exposures to individual people. And because of this, scientists know little about how specific pollutants—particularly in combination with each other, with diet, and with physical activity—affect any individual’s response to the pollutant. With a clear need for progress, exposure assessment has recently come under the spotlight. This year, the NIEHS launched the Exposure Biology Program (EBP), a four-year effort with two overarching goals: to improve exposure assessment technology, and to identify biomarkers for common pathogenic mechanisms that reflect the human response to environmental agents. Such biomarkers could include changes in metabolites, proteins, or DNA that reflect the individual’s genetic susceptibility to environmental harm. “Right now we don’t really understand how exposure levels translate to human health risk, so our goal is to fill that gap,” says EBP coordinator Brenda Weis, a senior scientific advisor at NIEHS. “We need to get a better measure of exposure at the point of human contact, and we need to integrate those measures with biological response measures derived from samples taken directly from exposed people. So, this is a more ‘medical’ approach to exposure assessment—in the sense that measures are taken on a personal level—rather than the broader, ecological approaches we’ve been using so far.”

Predicting the effect of substance abuse treatment on probationer recidivism

Support for the effectiveness of substance abuse treatment to reduce substance use and recidivism among populations supervised by the criminal justice system continues to grow in substance abuse and criminal justice literature. Recent studies show that a variety of programs including the Breaking the Cycle program and drug courts appear to result in improved outcomes for offenders. In this paper, we examine the effect of non-residential substance abuse treatment on arrest. Our data are for almost 134,000 ‘drug-involved’ individuals sentenced to probation in Florida between July 1995 and June 2000. Nearly 52,000 of these individuals received non-residential substance abuse treatment, while 81,797 did not. Our approach is a methodologically simple one that entails stratifying our data by treatment status, estimating logit and negative binomial models of arrest for each of the two datasets, and then applying each model to both datasets. This approach, which requires that both groups include subjects for whom treatment is appropriate, is analogous to using regression models to predict outcomes for new values of independent variables. For each observation in the dataset, we use the models to predict the expected outcomes for each individual under two scenarios – receiving non-residential treatment and receiving no treatment. Summing over these individual estimates provides an estimate of the total numbers of arrests that would be expected under different levels of population exposure to treatment. Results suggest that non-residential treatment reduced both the expected numbers of individuals who recidivated (i.e., were arrested) and the expected total numbers of arrests in the 12 and 24 months following placement on supervision.

Can lessons from public health disease surveillance be applied to environmental public health tracking?

Disease surveillance has a century-long tradition in public health, and environmental data have been collected at a national level by the U.S. Environmental Protection Agency for several decades. Recently, the Centers for Disease Control and Prevention announced an initiative to develop a national environmental public health tracking (EPHT) network with “linkage” of existing environmental and chronic disease data as a central goal. On the basis of experience with long-established disease surveillance systems, in this article we suggest how a system capable of linking routinely collected disease and exposure data should be developed, but caution that formal linkage of data is not the only approach required for an effective EPHT program. The primary operational goal of EPHT has to be the “treatment” of the environment to prevent and/or reduce exposures and minimize population risk for developing chronic diseases. Chronic, multifactorial diseases do not lend themselves to data-driven evaluations of intervention strategies, time trends, exposure patterns, or identification of at-risk populations based only on routinely collected surveillance data. Thus, EPHT should be synonymous with a dynamic process requiring regular system updates to a) incorporate new technologies to improve population-level exposure and disease assessment, b) allow public dissemination of new data that become available, c) allow the policy community to address new and emerging exposures and disease “threads,” and d) evaluate the effectiveness of EPHT over some appropriate time interval. It will be necessary to weigh the benefits of surveillance against its costs, but the major challenge will be to maintain support for this important new system.

Multimedia persistence as an indicator of potential for population‐level intake of environmental contaminants

Although intuitively it is apparent that population-level exposure to contaminants dispersed in the environment must be related to the persistence of the contaminant, there has been little effort to quantify this link formally. In this paper we investigate the relationship between overall persistence and/or overall residence time in a multimedia exposure environment and the population-level intake of contaminants as expressed by intake fraction (iF), the cumulative fraction of chemical emitted to the environment that is taken up by members of the population. We demonstrate that for any given contaminant and emission scenario the definition of iF implies that it is directly proportional to the overall multimedia persistence (Pov), or the overall multimedia residence time (Tov). The proportionality constant has dimensions of time and represents the characteristic time for population intake (CTI) of the chemical from the environment. We then apply the CalTOX fate and exposure model to explore how Tov and CTI combine to determine the magnitude of iF We find that CTI has a narrow range of possible values relative to Tov across multiple chemicals and emissions scenarios. We use data from the Canadian Environmental Protection Act Priority Substance List (PSL1) Assessments and multimedia Pov to show that exposure assessments based on empirical observation are consistent with interpretations from the model. Results indicate that Pov derived from screening-level assessments of persistence, bioaccumulation potential, and toxicity (PBT) is a useful indicator of the potential for population-level exposure.

Lead Levels in Urine of Never-Smoking Adult Women in Non-Polluted Areas in Japan, with References to Cadmium Levels in Urine

The present study was initiated to assess current level of general population exposure to lead (Pb) in terms of Pb in urine (Pb-U). For this purpose, spot urine samples were collected from 2,332 never-smoking adult women in 10 areas all-over Japan, and were subjected to analysis for Pb-U by graphite furnace atomic absorption (GFAA). Data on cadmium in urine (Cd-U) as measured by GFAA were cited from a previous publication). The grand geometric means (GM) for Pb-U as observed, as corrected for creatinine (cr) and as corrected for a specific gravity of 1.016 were 1.06 microg/l, 1.28 microg/g cr and 1.14 microg/l, respectively, with small intra- and inter-variations with geometric standard deviations of about 2 or less. Arithmetic means of the 10 GMs (one each for the 10 areas) were 1.05 microg/l, 1.19 microg/g cr and 1.18 microg/l, respectively. The levels observed appeared to be lower than levels reported for other populations in the world. Chronological comparison within Japan suggested a gradual decrease in Pb-U in past over 20 yr. No close correlation was detected between Pb-U and Cd-U.