Air pollution exposure monitoring and estimating. Part I. Integrated air quality monitoring system

This paper presents an integrated exposure monitoring system, based on an expansion of existing air quality monitoring systems using dispersion modelling. The system allows: (1) identifying geographical areas whose inhabitants are most exposed to ambient pollution; (2) identifying how many people in an area are exposed to concentrations of pollution exceeding air quality guidelines; (3) describing the exposure of population subgroups (e.g. children); (4) planning pollution abatement measures and quantifying their effects; (5) establishing risk assessment and management programs, and (6) investigating the short- and long-term effects of both pollutants and pollution sources on public health. The effect of pollution is rarely very large and in order to discover it, exposure estimation must provide data that reflects both spatial and temporal variations. Estimates of pollution exposure are obtained using an integrated approach that combines results of measurements from monitoring programs with dispersion calculations. These values can serve as estimates for individual short-term or long-term exposure. The grouped data allows the expression of ambient pollution concentrations as the spatial distribution of estimates such as the mean or 98th percentile of such compounds as SO2, O3, NO2, PM10 and PM2.5. This integrated approach has been combined into a single software package, AirQUIS.     

Estimated distributions of personal exposure to respirable particles

A method of estimating distributions of exposure to respirable particles is presented. Using pollutant monitoring data from outdoors and indoors, time-activity data and a time-weighted exposure model, means and variances for exposure distributions are generated. Variances are estimated using Gauss' law of error propagation. The model is calibrated using data from a personal monitoring study. Estimated distributions of exposure to respirable particles for children in six cities living in homes with and without smokers are presented. The implications of these estimates for air pollution epidemiology and needs for further research are discussed.     

The measurement procedure in the SEMONT monitoring system

The measurement procedure of the open area in situ electric field strength is presented, acquiring the real field data for testing of the Serbian electromagnetic field monitoring network (SEMONT) and its Internet portal. The SEMONT monitoring system introduces an advanced approach of wireless sensor network utilization for the continuous supervision of overall and cumulative level of electromagnetic field over the observed area. The aim of the SEMONT system is to become a useful tool for the national and municipal agencies for the environmental protection, regarding the electromagnetic pollution monitoring and the exposure assessment of the general population. Considering the public concern on the potentially harmful effects of the long-term exposure to electromagnetic radiation, as well as the public transparency principle that is incorporated into the Serbian law on non-ionizing radiation protection, the SEMONT monitoring system is designed for the long-term continuous monitoring, presenting real-time measurement results, and corresponding exposure assessment over the public Internet network.     

New approaches for assessment of occupational exposure to metals using on-site measurements

Traditional assessment of occupational exposure to metals typically involves static or personal aerosol sampling on a membrane filter followed by a laboratory determination of the metal content on the filter sample. These techniques give results with high accuracy and low detection limits. However, they all have a drawback in that, since the samples have to be analysed in a laboratory, the results will usually be obtained days or weeks after the sampling took place. Today there is available a new generation of portable electronic micro-balances and instruments for metal analysis based on X-ray fluorescence. These instruments will make on-site measurements of metal exposure possible, which opens the way for new approaches for assessment of occupational exposure to metals. In combination with high-flow pumps, short-term sampling is possible, which allows monitoring of the exposure variation during a work shift as well as the exposure during individual work tasks of short duration. Screening measurements and emission measurements are other examples of monitoring that are facilitated using on-site determinations. Measure control monitoring can effectively be performed using on-site measurements and is an effective tool in the assessment of workplace improvements. On-site determinations can also form an effective and pedagogic tool showing workers how to perform specific tasks and demonstrating the effectiveness of different measures intended to improve their work environment. Other examples are the assessment of skin exposure using aerosol deposition on pads and screening of contamination using bulk samples.     

Evaluation of the best compromise between the urban air quality monitoring resolution by diffusive sampling and resource requirements

The need to collect data representative of overall urban pollution is all-important in order to monitor the population exposure. High spatial resolution monitoring using diffusive samplers allows studying of the urban pollutant distribution, thus enabling deeper investigation of their generation and diffusion mechanisms. Nevertheless, such a monitoring campaign has a certain cost. In this study we point out how to find the best compromise between the number of necessary measurements and the affordable costs for monitoring campaigns. We also describe an innovative method for the proper design of a fixed urban monitoring network by means of preliminary high spatial resolution campaigns using diffusive samplers. Four European capital cities (Dublin, Madrid, Paris and Rome) were monitored six times, each time for seven days. Benzene, toluene, ethylbenzene, xylenes (BTEX) and NO(2) concentrations were measured at 146 sites in Dublin, 293 in Madrid, 339 in Paris and 290 in Rome. Multiscale grids have been drawn which ranged in mesh size from 500 m to 2 km. The statistical processing of data produced a twofold result: the creation of isoconcentration maps with geostatistical procedures, and an algorithm aimed at locating the minimum number of sampling sites where the fixed monitoring stations should be placed. Average urban levels estimated on the basis of these selected sites differ by less than 8% from those calculated on the whole populations of the sampled points. The aim of this work is to investigate how far the resolution of a monitoring campaign of urban pollution by diffusive sampling can be reduced, thus making the monitoring less expensive in terms of human and financial resources, while preserving the same quality of the results that could be achieved with a higher resolution. We found that there is no significant loss of information when the resolution of the monitoring grid for BTEX is lowered to a mesh size of 1.85 km, that is a sampling site each 3.4 km(2), and that the minimum number of sampling sites to be used is N = 0.29 A, where A is the urban surface to be monitored (in km(2)). As the spatial distribution of NO(2) is less sensitive to the distance from the emission source than that of BTEX, this relationship could be retained as a valid lower limit for the mesh grid size also for NO(2) monitoring.     

暴露声级监测方法探讨

在高铁现场监测数据基础上,根据环境监测经验确定了5种常见暴露声级测试的测量时间段,分别计算其暴露声级并对其结果进行分析讨论。研究结果表明:采样起止时间不同对暴露声级监测的影响误差在1 dB之内,并且在暴露声级测试时,建议选择T5对应的时间段,该结论为科学合理地环境监测提供了数据支撑。     

Development of a new method for the determination of residues of the neonicotinoid insecticide imidacloprid in juvenile chinook (Oncorhynchus tshawytscha) using ELISA detection

The neonicotinoid insecticide imidacloprid (IMI) has been proposed as an alternative to carbaryl for controlling indigenous burrowing shrimp on commercial oyster beds in Willapa Bay and Grays Harbor, Washington. A focus of concern over the use of this insecticide in an aquatic environment is the potential for adverse effects from exposure to non-target species residing in the Bay, such as juvenile Chinook (Oncorhynchus tshawytscha) and cutthroat trout (O. clarki). Federal registration and State permiting approval for the use of IMI will require confirmation that the compound does not adversely impact these salmonids following field applications. This will necessitate an environmental monitoring program for evaluating exposure in salmonids following the treatment of beds. Quantification of IMI residues in tissue can be used for determining salmonid exposure to the insecticide. Refinement of an existing protocol using liquid-chromatography mass spectrometry (LC-MS) detection would provide the low limits of quantification, given the relatively small tissue sample sizes, necessary for determining exposure in individual fish. Such an approach would not be viable for the environmental monitoring effort in Willapa Bay and Grays Harbor due to the high costs associated with running multiple analyses, however. A new sample preparation protocol was developed for use with a commercially available enzyme-linked immunosorbent assay (ELISA) for the quantification of IMI, thereby providing a low-cost alternative to LC-MS for environmental monitoring in Willapa Bay and Grays Harbor. Extraction of the analyte from the salmonid brain tissue was achieved by Dounce homogenization in 4.0 mL of 20.0 mM Triton X-100, followed by a 6 h incubation at 50-55 °C. Centrifugal ultrafiltration and reversed phase solid phase extraction were used for sample cleanup. The limit of quantification for an average 77.0 mg whole brain sample was calculated at 18.2 μg kg(-1) (ppb) with an average recovery of 79%. This relatively low limit of quantification allows for the analysis of individual fish. Using controlled laboratory studies, a curvelinear relationship was found between the measured IMI residue concentrations in brain tissue and exposure concentrations in seawater. Additonally, a range of IMI brain residue concentrations was associated with an overt effect; illustrating the utility of the IMI tissue residue quantification approach for linking exposure with defined effects.     

环境监测点位“组合校验码”编码模型及编码管理系统设计

分析了环境监测点位编码管理中存在的问题,提出科学合理的编码应该是具有科学性、唯一性、稳定性、简明性、规范性、可扩展性等特点。设计了一种简单"组合校验码"模型来适应不同环境要素类型的环境监测工作需要。同时,设计了一套覆盖各层级环境监测机构,各种环境要素类型,适应市场化监测服务,满足不同点位管控类别的编码管理系统来支撑"组合校验码"模型的使用,通过该系统可以有效解决环境监测数据集成程度低、共享困难等问题。     

Comparison of Nitrate Levels in Raw Water and Finished Water from Historical Monitoring Data on Iowa Municipal Drinking Water Supplies

Nitrate contamination of water sources is a concern where large amounts of nitrogen fertilizers are regularly applied to soils. Ingested nitrate from dietary sources and drinking water can be converted to nitrite and ultimately to N-nitroso compounds, many of which are known carcinogens. Epidemiologic studies of drinking water nitrate and cancer report mixed findings; a criticism is the use of nitrate concentrations from retrospective drinking water data to assign exposure levels. Residential point-of-use nitrate data are scarce; gaps in historical data for municipal supply finished water hamper exposure classification efforts. We used generalized linear regression models to estimate and compare historical raw water and finished water nitrate levels (1960s--1990s) in single source Iowa municipal supplies to determine whether raw water monitoring data could supplement finished water data to improve exposure assessment. Comparison of raw water and finished water samples (same sampling date) showed a significant difference in nitrate levels in municipalities using rivers; municipalities using other surface water or alluvial groundwater had no difference in nitrate levels. A regional aggregation of alluvial groundwater municipalities was constructed based on results from a previous study showing regional differences in nitrate contamination of private wells; results from this analysis were mixed, dependent upon region and decade. These analyses demonstrate using historical raw water nitrate monitoring data to supplement finished water data for exposure assessment is appropriate for individual Iowa municipal supplies using alluvial groundwater, lakes or reservoirs. Using alluvial raw water data on a regional basis is dependent on region and decade.     

多源环境监测信息交换模型的设计与实现

针对环境监测系统现有的污染源管理、饮用水管理、噪声管理、自动监测管理等信息系统存在异构化、多源化等现象,造成数据重复录入、数据不一致、资源浪费等问题,展示了一种数据交换模型的设计思路和实现方法,介绍模型的数据抽取、数据封装、数据传递、数据解析、数据映射、校验和转换、数据接收等多个环节。该数据交换模型已成功实现与多个外部业务系统数据对接,现每天采集的数据超过5 000条,系统运行稳定、性能良好。     

A novel environmental indicator for monitoring of pesticides

The identification of an indicator for monitoring pesticides is a very effective analytical approach because it allows one to schedule and simplify the analytical routine. In this study, a new indicator has been designed, which has to be able to define a scale of priorities in the pesticides monitoring. A starting equation was developed involving the escaping tendency of a given substance from a phase (based on the Mackay model I level). The reliability of the indicator was tested by application to a model system, consisting of a defined and limited area, choosing water as matrix over a period of 6 years. A group of marker compounds was also defined to implement the predictive efficacy of the indicator. The results obtained by modeling were compared to those obtained by experimentation of the same model system. The indicator was subsequently and appropriately modified creating a new equation, including a kinetic factor, which considers the environmental degradation processes. The effect of the rectified indicator was consistent with the sales data list of compounds, when applied to the markers. The indicator developed in this study, tested as a model on specific area-phase-period (Province of Siena, water phase, 2000?C2006), is applicable to any other area-phase-period, adjusting the partition value of the Mackay model for the case under study.     

Risk assessment near uncontrolled hazardous waste sites: Role of monitoring data

The traditional approach of coupling estimates of human exposures to individual chemicals with laboratory studies of the toxicity of the chemicals as the basis for quantitative assessments of risk is not adequate when considering problems near hazardous waste sites. For example, there are (a) too many chemicals and mixtures involved, (b) containment uncertainties, and (c) future exposure problems associated with groundwater and soil contamination. Among the items to be considered in expanding the dimensions of risk assessment methodologies of the past are (a) identification of chemical groups or of dominant toxic chemicals of principal concern and the likely man-made as well as natural pathways for environmental migration, (b) the role of biological monitoring in addition to traditional monitoring approaches, and (c) the coupling of monitoring data with past, current, and future population activity patterns and with epidemiological and other health data.Monitoring data is a key in risk assessments since there is little likelihood that materials balances or modelling will provide authoritative information concerning exposure levels. The use of monitoring data from control areas and from nationwide baseline surveys in developing comparative risk assessments is particularly important. Finally, recent experience provides us with a number of practical guidelines for designing and carrying out monitoring programs that will provide authoritative and useful data. *** DIRECT SUPPORT *** AZ802019 00002     

Guidance on choosing a measuring instrument for indoor particle pollution studies

The possibility of acquiring real-time concentration data is leading many indoor air quality and health researchers to the use of particle measuring instruments instead of the classic filtration approach. This paper summarizes a checklist of characteristics that have to be considered on the selection of such instruments and checks the compliance of three air monitoring devices suitable for environmental exposure researches. An evaluation table with desirable instrument technical, economic, and logistics characteristics was summarized in a checklist, and spec sheets of three air monitoring devices suitable for environmental exposure researches were checked. Technical, economic, and logistics aspects have to be considered. Suitability, measurement range, accuracy, resolution, and robustness are indispensable metrological characteristics. Only one instrument was in comply with it. A popular air monitoring device among environmental exposure researchers was checked and it failed the accuracy check. When selecting a particle measuring instrument, technical, economic, and logistics aspects have to be considered. Suitability, measurement range, accuracy, resolution, and robustness are indispensable metrological characteristics. When selecting an instrument for a study, a lack of information on the quality of results is a strong indication that it should not be considered, as study's response may be compromised.     

A comparative study of respirable particulate microenvironmental concentrations and personal exposures

Personal monitoring (PM) for respirable suspended particulate matter (RSP) of thirty subjects was performed as part of an air pollution health effects study conducted in Houston, Texas. Parallel RSP measurements were performed in the study subjects' homes and two fixed site monitoring stations. The participants' daytime activities were independently recorded by study techicians. These data were used to characterize RSP concentrations in each microenvironment visited by the participants. Four estimates of daytime exposure to RSP were calculated based on two different microenvironmental models, and home and fixed site mean daytime RSP concentrations. These estimates were compared to mean daytime personal exposure from PM. Hourly estimates of exposure were calculated from a microenvironmental model and mean hourly home RSP concentrations and compared to hourly PM data. The results of the study indicate that, as in the case of NO₂, it is important to characterize indoor microenvironmental RSP concentrations according to location, sources, and concurrent activities, both qualitatively and quantitatively. Stratification of concentrations according to sources present and self-reported activity can lead to misclassification of exposures. For RSP and, probably, other pollutants with indoor sources and with short exposure integration times, adequate measures of exposure can only be obtained with very detailed and complex microenvironmental models or comprehensive personal monitoring.     

Prioritizing GM crop monitoring sites in the dynamics of cultivation systems and their environment

EU legislation stipulates that GM crops have to be monitored for potential adverse environmental effects. Monitoring preferably should take place in the most exposed areas-the cultivated fields and their neighbouring environment. Current monitoring designs do not give detailed consideration to the different exposure intensities in agricultural practice. At the same time, the selection of specific, more exposed sites is difficult considering the dynamic and diversity of crop cultivation and rotation systems and their environments. We developed an approach for prioritising the monitoring of on-farm and neighbouring sites based on differing exposure levels using a minimum dataset of cultivation and land use information. Applying a Bt-maize cultivation scenario to Brandenburg, Germany, where presently no GM crops are cultivated, we systemised and categorised areas with different spatio-temporal exposure intensities including 50 m, 200 m and 1000 m buffers. These categories correspond to different suitabilities to serve as monitoring sites. Sites are prioritised using a sequential scheme. This yields an improved and objective spatial monitoring design providing detailed exposure information. This methodology is flexible and transferable to any agricultural setting, therefore enabling superior statistical comparisons between locations and regions and thus enhancing monitoring data quality.     

流域水环境监测质量管理系统设计与实现

目前的水环境监测工作需要建立统一的水环境监测质量管理系统,这对于各级、各地水环境监测质量控制信息的规范化录入和分级汇总统计、信息共享具有重要的意义.在分析目前水环境监测质量管理存在问题的基础上,基于网络服务、地理信息等技术,设计实现了水环境监测质量管理系统.利用该系统,各级、各地水环境监测质量管理部门能够进行监测机构、持证人员、监测项目、仪器设备等信息的录入和定期维护,同时共享监测方法、政策法规、标准规范、标准物质等信息.同时上级管理部门能够查看、统计所辖部门的水环境监测质量控制信息,从而为流域水环境突发事件应急资源调配、辅助决策等提供信息支撑.     

Urgent problems of improving background air pollution monitoring systems

For more than 12 years, systematic observations of background air pollution have been carried out in accordance with the WMO Programme using the network of USSR stations located in sparsely populated settlements and in a number of neighbouring cities. The parameters involved include spectral radiation measurements, determination of chemical composition of precipitation and the concentrations of a number of atmospheric pollutants. Analysis of the data obtained allows conclusions to be drawn on the capabilities of the current system and to evaluate methods of improving it.In order to further improve the monitoring system, it is recommended that the system should perform the same observations on air pollution and precipitation as carried out by other international and national programs, and also to create centralized laboratories to deal with the analysis of samples from these monitoring stations. Additionally, solid sorbents are emerging as an effective means of sampling certain air pollutants. They may be sent by post, they increase the accuracy of measurements and allow air sampling intervals of up to 7–10 days, thus synchronizing this period with the interval of precipitation sampling.     

Some international activities in environmental health monitoring and surveillance

Environmental health monitoring and surveillance include activities such as collection of information on the production and use of chemicals; preparation of inventories of waste discharges; measurement of physical, chemical and biological agents in air, water and food, at work place and at home; epidemiological investigations, and collection and analysis of environmental, and health statistical data. There are two main objectives of these activities: estimation of human exposure to potentially harmful environmental factors and timely detection of adverse health effects; and the assessment of environmental conditions in relation to established guidelines and standards. Environmental health monitoring and surveillance projects initiated, organized and implemented by the Specialized Agencies and other bodies of the United Nations system include monitoring of air and water quality and of food and animal feed contamination; pilot projects on air pollution exposure assessment and biological monitoring; and ionizing radiation surveillance. Principles of environmental and health monitoring in occupational environment, and of monitoring and surveillance of environmental health effects are outlined. Two examples are provided of national environmental health surveillance systems.Revised and up-dated text of a paper presented at the World congress on Environmental Health in Development Planning, Mexico City, November 1979.Formerly Manager, Environmental Health Criteria and Standards, and Chief Central Unit, International Programme on Chemical Safety, Division of Environmental Health, World Health Organization, Geneva, Switzerland.     

Exposure estimates for the Houston Area Asthma Study

Procedures for determining exposure extimates for the Houston Area Asthma Study are discussed. Two residential clusters of asthmatics in the Houston area have been studied as part of an overall attempt to assess the health effects of air pollution in the Texas Gulf Coast area. Air pollutant exposure data have been produced according to a three-tier monitoring scheme, i.e. (1) continuous data from centrally-located fixed stations, (2) residential indoor/outdoor measurements, and (3) personal monitoring. This air monitoring network should yield estimates of individual exposures for use in health effect correlations.The fixed sites and mobile continuously monitor ambient levels of ozone, nitrogen oxides, sulfur dioxide, carbon monoxide, and meteorological parameters (wind speed, wind direction, temperature, dew point, solar irradiation, and precipitation). Continuous sequential integrated sampling is preformed for total suspended particulates (TSP) and, inhalable particulates (IP) (total of < 2.5m and 2.5–15.0 m) by dichotomous samplers for 24 hr samplers), aldehydes (bubblers), and aeroallergens (intermittent rotorod samplers). In addition to gravimetric determinations, particulate filters are routinely analyzed for sulfate, nitrate, and (every third day) trace elements. Personal monitoring includes ozone, respirable particles, nitrogen dioxide and formaldehyde. A quality assurance/control program that meets specifications established in the EPA Quality Assurance Handbook for air pollution measurement systems was implemented. Examples of results consisting of unvalidated preliminary data from the monitoring for ozone for three participants is presented and approaches to determining exposure estimates are discussed for both an integrated exposure estimate and short time period exposure estimate.(These studies have been funded by the U.S. Environmental Protection Agency through Cooperative Agreement CR 807108010 and Grant R 808738010. Statements made in this article should not be taken as Agency policy.)