The Experts below are selected from a list of 250365 Experts worldwide ranked by ideXlab platform
Tony Fletcher - One of the best experts on this subject based on the ideXlab platform.
-
use of public water supply fluoride concentration as an indicator of Population Exposure to fluoride in england 1995 2015
Environmental Monitoring and Assessment, 2020Co-Authors: Tony Fletcher, David J. Roberts, J. Morris, A. Wood, N. Q. Verlander, Giovanni LeonardiAbstract:Public health monitoring of Community Water Fluoridation (CWF) schemes requires estimates of Exposure to fluoride in public water supplies (PWS). We aimed to use routine data to estimate Population Exposure to PWS-fluoride in England and to determine whether PWS-fluoride Exposure from 2005 to 2015 could be used as a proxy for Exposure for 1995–2004, when fluoride concentration data that could be linked to Population health data were unavailable. We calculated annual mean water supply zone PWS-fluoride concentrations from monitoring data for 1995–2015, stratified by fluoridation scheme-flagging. We allocated annual 2005–2015 mean PWS-fluoride concentrations to small area boundaries to describe Population Exposure within five concentration categories (< 0.1 to ≥ 0.7 mg/L). We compared zone-level 1995–2004 and 2005–2015 mean PWS-fluoride concentrations using Spearman correlation. Most (72%) of the Population received PWS with < 0.2 mg/L fluoride and 10% with ≥ 0.7 mg/L. Fluoride concentrations in 1995–2004 and 2005–2015 were similar (median 0.11 mg/L (lower quartile–upper quartile (LQ–UQ) 0.06–0.17) and 0.11 mg/L (LQ–UQ 0.07–0.17), respectively) and highly correlated (coefficient 0.93) if un-fluoridated but differed (1995–2004 median 0.78 mg/L (LQ–UQ 0.59–0.92); 2005–2015 0.84 mg/L (LQ–UQ 0.72–0.95)) and correlated weakly (coefficient 0.31) if fluoridated. Fluoride concentrations in 2005–2015 approximate those in 1995–2004 but with a greater risk of misclassification in fluoridation schemes.
-
Use of Public Water Supply Fluoride Concentration as an Indicator of Population Exposure to Fluoride in England 1995-2015
ISEE Conference Abstracts, 2018Co-Authors: Giovanni Leonardi, David J. Roberts, N. Q. Verlander, John W. Morris, Diane Edwards, Tony FletcherAbstract:Studies of Exposure to fluoride may use Geographic Information Systems to estimate Population Exposure by geo-referencing water supply zone (WSZ) monitoring data for public water supplies (PWS) to ...
-
Impact and uncertainty of a traffic management intervention: Population Exposure to polycyclic aromatic hydrocarbons.
The Science of the total environment, 2008Co-Authors: Sotiris Vardoulakis, Zaid Chalabi, Tony Fletcher, Chris Grundy, Giovanni S LeonardiAbstract:In urban areas, road traffic is a major source of carcinogenic polycyclic aromatic hydrocarbons (PAH), thus any changes in traffic patterns are expected to affect PAH concentrations in ambient air. Exposure to PAH and other traffic-related air pollutants has often been quantified in a deterministic manner that disregards the various sources of uncertainty in the modelling systems used. In this study, we developed a generic method for handling uncertainty in Population Exposure models. The method was applied to quantify the uncertainty in Population Exposure to benzo[a]pyrene (BaP) before and after the implementation of a traffic management intervention. This intervention would affect the movement of vehicles in the studied area and consequently alter traffic emissions, pollutant concentrations and Population Exposure. Several models, including an emission calculator, a dispersion model and a Geographic Information System were used to quantify the impact of the traffic management intervention. We established four Exposure zones defined by distance of residence postcode centroids from major road or intersection. A stochastic method was used to quantify the uncertainty in the Population Exposure model. The method characterises uncertainty using probability measures and propagates it applying Monte Carlo analysis. The overall model predicted that the traffic management scheme would lead to a minor reduction in mean Population Exposure to BaP in the studied area. However, the uncertainty associated with the Exposure estimates was much larger than this reduction. The proposed method is generic and provides realistic estimates of Population Exposure to traffic-related pollutants, as well as characterises the uncertainty in these estimates. This method can be used within a decision support tool to evaluate the impact of alternative traffic management policies.
Theodore Glickman - One of the best experts on this subject based on the ideXlab platform.
-
MINIMAX Population Exposure IN ROUTING HIGHWAY SHIPMENTS OF HAZARDOUS MATERIALS
Transportation Research Record, 1997Co-Authors: Erhan Erkut, Theodore GlickmanAbstract:A routing model for hazardous materials with two objectives—to minimize maximum Population Exposure and to minimize total travel time—is introduced. The Population Exposure is quantified by the number of people in an impact circle of a selected radius. To solve this two-objective problem, the focus is placed on the second objective, with a constraint on the first objective. This results in a problem that is easy to solve and has a solution that is easy to interpret. To demonstrate the use of this model, a case of nuclear waste shipments (i.e., spent fuel) in the United States in considered. The model is applied, with two bounds on high-level Population Exposure, to 10 nuclear waste origins. The results of this application are reported. The model behaves in a predictable (and desirable) way, avoiding major Population centers via detours. With its ability to quantify trade-offs between competing objectives, and its capacity to generate multiple routes for a shipment, the model has the potential to serve in ...
-
Minimax Population Exposure in Routing Highway Shipments of Hazardous Materials
Transportation Research Record: Journal of the Transportation Research Board, 1997Co-Authors: Erhan Erkut, Theodore GlickmanAbstract:A routing model for hazardous materials with two objectives—to minimize maximum Population Exposure and to minimize total travel time—is introduced. The Population Exposure is quantified by the number of people in an impact circle of a selected radius. To solve this two-objective problem, the focus is placed on the second objective, with a constraint on the first objective. This results in a problem that is easy to solve and has a solution that is easy to interpret. To demonstrate the use of this model, a case of nuclear waste shipments (i.e., spent fuel) in the United States in considered. The model is applied, with two bounds on high-level Population Exposure, to 10 nuclear waste origins. The results of this application are reported. The model behaves in a predictable (and desirable) way, avoiding major Population centers via detours. With its ability to quantify trade-offs between competing objectives, and its capacity to generate multiple routes for a shipment, the model has the potential to serve in a decision-support role for planning hazardous materials routes.
Martin Otto Paul Ramacher - One of the best experts on this subject based on the ideXlab platform.
-
Integrating Modes of Transport in a Dynamic Modelling Approach to Evaluate Population Exposure to Ambient NO2 and PM2.5 Pollution in Urban Areas
International journal of environmental research and public health, 2020Co-Authors: Martin Otto Paul Ramacher, Matthias KarlAbstract:To evaluate the effectiveness of alternative policies and measures to reduce air pollution effects on urban citizen’s health, Population Exposure assessments are needed. Due to road traffic emissions being a major source of emissions and Exposure in European cities, it is necessary to account for differentiated transport environments in Population dynamics for Exposure studies. In this study, we applied a modelling system to evaluate Population Exposure in the urban area of Hamburg in 2016. The modeling system consists of an urban-scale chemistry transport model to account for ambient air pollutant concentrations and a dynamic time-microenvironment-activity (TMA) approach, which accounts for Population dynamics in different environments as well as for infiltration of outdoor to indoor air pollution. We integrated different modes of transport in the TMA approach to improve Population Exposure assessments in transport environments. The newly developed approach reports 12% more total Exposure to NO2 and 19% more to PM2.5 compared with Exposure estimates based on residential addresses. During the time people spend in different transport environments, the in-car environment contributes with 40% and 33% to the annual sum of Exposure to NO2 and PM2.5, in the walking environment with 26% and 30%, in the cycling environment with 15% and 17% and other environments (buses, subway, suburban, and regional trains) with less than 10% respectively. The relative contribution of road traffic emissions to Population Exposure is highest in the in-car environment (57% for NO2 and 15% for PM2.5). Results for Population-weighted Exposure revealed Exposure to PM2.5 concentrations above the WHO AQG limit value in the cycling environment. Uncertainties for the Exposure contributions arising from emissions and infiltration from outdoor to indoor pollutant concentrations range from −12% to +7% for NO2 and PM2.5. The developed “dynamic transport approach” is integrated in a computationally efficient Exposure model, which is generally applicable in European urban areas. The presented methodology is promoted for use in urban mobility planning, e.g., to investigate on policy-driven changes in modal split and their combined effect on emissions, Population activity and Population Exposure.
-
Urban Population Exposure to NO x emissions from local shipping in three Baltic Sea harbour cities – a generic approach
Atmospheric Chemistry and Physics, 2019Co-Authors: Martin Otto Paul Ramacher, Matthias Karl, Johannes Bieser, Jukka-pekka Jalkanen, Lasse JohanssonAbstract:Abstract. Ship emissions in ports can have a significant impact on local air quality (AQ), Population Exposure and therefore human health in harbour cities. We determined the impact of shipping emissions in harbours on local AQ and Population Exposure in the Baltic Sea harbour cities Rostock (Germany), Riga (Latvia) and the urban agglomeration of Gdansk–Gdynia (Poland) for 2012. An urban AQ study was performed using a global-to-local chemistry transport model chain with the EPISODE-CityChem model for the urban scale. We simulated NO2 , O3 and PM concentrations in 2012 with the aim of determining the impact of local shipping activities on Population Exposure in Baltic Sea harbour cities. Based on simulated concentrations, dynamic Population Exposure to outdoor NO2 concentrations for all urban domains was calculated. We developed and used a novel generic approach to model dynamic Population activity in different microenvironments based on publicly available data. The results of the new approach are hourly microenvironment-specific Population grids with a spatial resolution of 100 m × 100 m. We multiplied these grids with surface pollutant concentration fields of the same resolution to calculate total Population Exposure. We found that the local shipping impact on NO2 concentrations is significant, contributing 22 %, 11 % and 16 % to the total annually averaged grid mean concentration for Rostock, Riga and Gdansk–Gdynia, respectively. For PM 2.5 , the contribution of shipping is substantially lower, at 1 %–3 %. When it comes to microenvironment-specific Exposure to annual NO2 , the highest Exposure to NO2 from all emission sources was found in the home environment (54 %–59 %). Emissions from shipping have a high impact on NO2 Exposure in the port area (50 %–80 %), while the influence in home, work and other environments is lower on average (3 %–14 %) but still has high impacts close to the port areas and downwind of them. Besides this, the newly developed generic approach allows for dynamic Population-weighted outdoor Exposure calculations in European cities without the necessity of individually measured data or large-scale surveys on Population data.
Matthias Karl - One of the best experts on this subject based on the ideXlab platform.
-
Integrating Modes of Transport in a Dynamic Modelling Approach to Evaluate Population Exposure to Ambient NO2 and PM2.5 Pollution in Urban Areas
International journal of environmental research and public health, 2020Co-Authors: Martin Otto Paul Ramacher, Matthias KarlAbstract:To evaluate the effectiveness of alternative policies and measures to reduce air pollution effects on urban citizen’s health, Population Exposure assessments are needed. Due to road traffic emissions being a major source of emissions and Exposure in European cities, it is necessary to account for differentiated transport environments in Population dynamics for Exposure studies. In this study, we applied a modelling system to evaluate Population Exposure in the urban area of Hamburg in 2016. The modeling system consists of an urban-scale chemistry transport model to account for ambient air pollutant concentrations and a dynamic time-microenvironment-activity (TMA) approach, which accounts for Population dynamics in different environments as well as for infiltration of outdoor to indoor air pollution. We integrated different modes of transport in the TMA approach to improve Population Exposure assessments in transport environments. The newly developed approach reports 12% more total Exposure to NO2 and 19% more to PM2.5 compared with Exposure estimates based on residential addresses. During the time people spend in different transport environments, the in-car environment contributes with 40% and 33% to the annual sum of Exposure to NO2 and PM2.5, in the walking environment with 26% and 30%, in the cycling environment with 15% and 17% and other environments (buses, subway, suburban, and regional trains) with less than 10% respectively. The relative contribution of road traffic emissions to Population Exposure is highest in the in-car environment (57% for NO2 and 15% for PM2.5). Results for Population-weighted Exposure revealed Exposure to PM2.5 concentrations above the WHO AQG limit value in the cycling environment. Uncertainties for the Exposure contributions arising from emissions and infiltration from outdoor to indoor pollutant concentrations range from −12% to +7% for NO2 and PM2.5. The developed “dynamic transport approach” is integrated in a computationally efficient Exposure model, which is generally applicable in European urban areas. The presented methodology is promoted for use in urban mobility planning, e.g., to investigate on policy-driven changes in modal split and their combined effect on emissions, Population activity and Population Exposure.
-
Urban Population Exposure to NO x emissions from local shipping in three Baltic Sea harbour cities – a generic approach
Atmospheric Chemistry and Physics, 2019Co-Authors: Martin Otto Paul Ramacher, Matthias Karl, Johannes Bieser, Jukka-pekka Jalkanen, Lasse JohanssonAbstract:Abstract. Ship emissions in ports can have a significant impact on local air quality (AQ), Population Exposure and therefore human health in harbour cities. We determined the impact of shipping emissions in harbours on local AQ and Population Exposure in the Baltic Sea harbour cities Rostock (Germany), Riga (Latvia) and the urban agglomeration of Gdansk–Gdynia (Poland) for 2012. An urban AQ study was performed using a global-to-local chemistry transport model chain with the EPISODE-CityChem model for the urban scale. We simulated NO2 , O3 and PM concentrations in 2012 with the aim of determining the impact of local shipping activities on Population Exposure in Baltic Sea harbour cities. Based on simulated concentrations, dynamic Population Exposure to outdoor NO2 concentrations for all urban domains was calculated. We developed and used a novel generic approach to model dynamic Population activity in different microenvironments based on publicly available data. The results of the new approach are hourly microenvironment-specific Population grids with a spatial resolution of 100 m × 100 m. We multiplied these grids with surface pollutant concentration fields of the same resolution to calculate total Population Exposure. We found that the local shipping impact on NO2 concentrations is significant, contributing 22 %, 11 % and 16 % to the total annually averaged grid mean concentration for Rostock, Riga and Gdansk–Gdynia, respectively. For PM 2.5 , the contribution of shipping is substantially lower, at 1 %–3 %. When it comes to microenvironment-specific Exposure to annual NO2 , the highest Exposure to NO2 from all emission sources was found in the home environment (54 %–59 %). Emissions from shipping have a high impact on NO2 Exposure in the port area (50 %–80 %), while the influence in home, work and other environments is lower on average (3 %–14 %) but still has high impacts close to the port areas and downwind of them. Besides this, the newly developed generic approach allows for dynamic Population-weighted outdoor Exposure calculations in European cities without the necessity of individually measured data or large-scale surveys on Population data.
Patrick Levallois - One of the best experts on this subject based on the ideXlab platform.
-
The assessment of Population Exposure to chlorination by-products: a study on the influence of the water distribution system
Environmental health : a global access science source, 2010Co-Authors: Christelle Legay, Manuel J. Rodriguez, Jean Sérodes, Patrick LevalloisAbstract:Background: The relationship between chlorination by-products (CBPs) in drinking water and human health outcomes has been investigated in many epidemiological studies. In these studies, Population Exposure assessment to CBPs in drinking water is generally based on available CBP data (e.g., from regulatory monitoring, sampling campaigns specific to study area). Since trihalomethanes (THMs) and haloacetic acids (HAAs) are the most documented CBP classes in drinking water, they are generally used as indicators of CBP Exposure. Methods: In this paper, different approaches to spatially assign available THM and HAA concentrations in drinking water for Population Exposure assessment purposes are investigated. Six approaches integrating different considerations for spatial variability of CBP occurrence within different distribution systems are compared. For this purpose, a robust CBP database (i.e., high number of sampling locations selected according to system characteristics) corresponding to nine distribution systems was generated. Results and conclusion: The results demonstrate the high impact of the structure of the distribution system (e.g., presence of intermediary water infrastructures such as re-chlorination stations or reservoirs) and the spatial variability of CBPs in the assigned levels for Exposure assessment. Recommendations for improving the Exposure assessment to CBPs in epidemiological studies using available CBP data from water utilities are also presented.