Exposure estimates in assessing helath effects of air pollution

Air pollution has been associated with adverse health effects. Difficulties in interpreting studies of health effects of exposure to air pollution arise in estimating exposure. Until recently, studies of effects of air pollution have relied on pollution exposure measurements obtained from fixed location air pollution stations monitoring outside air (to evaluate compliance with air quality standards, rather than to examine population exposure). However, recent evidence suggests that there are substantial differences between air pollution levels measured at such sites and levels to which people are actually exposed, i.e. personal exposure. The present study examines effects of ambient urban air pollution on persons suffering from asthma, healthy non-asthmatic subjects and school children (in 2 Canadian cities, Toronto and Hamilton). Air pollution exposure is being assessed by data obtained from: (1) conventional abatement oriented fixed location air pollution monitoring stations, (2) an extensive population oriented network, (3) inside and (4) outside structures (homes and schools) as well as (5) personal air pollution samplers. The data indicate variability in these different estimates of exposure which have implications on health effects assessment.     

Comparative Studies on the Usefulness of Seven Ecological Indices for the Marine Coastal Monitoring Close to the Shore on the Swedish East Coast

The simultaneous behaviour of seven ecological indices(Hurlberts, Margalefs, Menhinicks, Shannons,species number, Jaccards and saprobic index) wasstudied based on phytoplankton data close to the shoreon the East coast of Sweden during the summer 1998.The sampling stations had a similar eutrophicationlevel and were located in bays. Standard phytoplanktondatabases were used in calculating the indices, whichwere later compared using cluster analysis.Hurlberts, Margalefs, Menhinicks, Shannons andspecies number indices, as measure of communitydiversity, produced similar trends which oftendiffered from those based on Jaccards index ofsimilarity. However, the simultaneous use of theseindices was found meaningful as a possible part of themonitoring close to the shore. The application of asaprobic index lead to erroneous conclusions in thestudied case.     

Routine Measurement of Dissolved Inorganic 15N in Precipitation and Streamwater

The difficulty of measuring 15N in dilute solutions has limited the potential of ecosystem labeling experiments and model comparisons. By concentrating the N from large (up to 20 L) water samples on ion-exchange resin columns, we obtained enough N for accurate and reproducible 15N measurement using the Teflon tape diffusion method. Analysis of standards demonstrated >95% recovery of inorganic N from samples, and 15N values comparable to those obtained using standard distillation methods. The value of the blank at our laboratory was 0.16 moles N. Analytical precision was within 2 15N when samples of streamwater from the Bear Brook Watersheds (1800 eq · ha-1 · yr-1 N addition at 192 15N) were kept frozen until analysis. The analytical process is lengthy, but once set up can easily be performed for large numbers of samples.     

Methane in ocean waters: Concentration and carbon isotope variability at East Pacific Rise and in the Arabian Sea

Methane concentrations and stable carbon isotope ratios of water samples from the East Pacific Rise (EPR) at 21°S and the Arabian Sea (24°N, 65°E) have been determined. EPR surface water is in equilibrium (ca. 50 nl/L and –50<¹³CH₄<–46) with atmospheric methane. Deep background water has the signature of the remaining fraction of atmospheric methane partially oxidized in the water column by bacteria. Bottom near, hydrothermally influenced vent methane (>100nl/L and –30<¹³CH₄<–22) is detectable only close to the seep site. There is no input of hydrothermal methane into the atmosphere. EPR water is considered to be rather a sink than a source of atmospheric methane. Surface waters of the Arabian Sea are enriched in methane relative to the atmosphere (source for atmospheric methane). Carbon isotope ratios point to a bacterial origin of methane (¹³CH₄<–55) that is generated in the surface waters. Concentration changes and variations of carbon isotope ratios also suggest that methane seeping from the sea floor sediments of the Arabian Sea is oxidized by bacterial activity and does not reach the atmosphere.     

Heavy metal concentration in the moss Pleurozium schreberi in the Niepołomice Forest,Poland: changes during 20 years

The Niepoomice Forest is a large forestcomplex (110 km²) situated in southern Poland 10 to 30 kmto the east of the urban industrial Kraków agglomeration andsteelworks, which was built up on the outskirts of the city in1950. Due to prevailing westerly winds, the forest is affectedby pollutants emitted by both the steelworks and the city. Thelevel of heavy metal contamination in the Niepoomice Forestwas described using a sensitive bioindicator – the moss Pleurozium schreberi. Mean concentrations of metals in mosscollected in the Niepoomice Forest were Cd – 0.71, Cr – 2.4,Cu – 8.6, Fe – 673, Pb – 12.7, and Zn – 61 mg/kg.Concentrations of heavy metals in moss in the NiepoomiceForest decreased in time. As compared with the relatively cleanarea in north-eastern Poland (Puszcza Biaowieska), the concentration of Fe was 2–9 fold and Pb 4–6 fold higher in theNiepoomice Forest in 1975, while in 1998 4 fold and 2 fold,respectively. In both 1975 and 1998 the most polluted by heavymetals was the western part of the Niepoomice Forest (closestto the pollution sources) and the area along the roads insidethe forest complex.     

Soil-Water Partitioning and Desorption Hysteresis of Volatile Organic Compounds from a Louisiana Superfund Site Soil

The adsorption and desorption of three volatile organic compounds (1,2- dichloroethane, 1,1,2- trichloroethane and 1,1,2,2-tetrachloroethane) from a previously uncontaminated clayey soil sample from a Superfund site in North Baton Rouge,Louisiana was studied. In the linear range of the adsorption isotherm, the partition constants were not affected by the presence of the co-solutes. The adsorption isotherms over a wide concentration range on the soil followed the nonlinearFreundlich isotherm. The desorption of the compounds showedsignificant hysteresis at all concentrations studied. Approximately 20 to 70% of the adsorbed mass of organic compounds resisted the desorption even after five months ofsuccessive desorption steps. The desorption of four compounds(1,2-dichloroethane, 1,1,2-trichloroethane, 1,4-dichlorobenzeneand hexachlorobutadiene) from a contaminated soil sample fromthe same site was also studied. The aqueous concentration declined as the successive desorption steps progressed. For hexachlorobutediene the desorption can be visualized as occurring in two stages. The first stage involved a loosely bound or reversible fraction and the second stage involveda tightly bound or resistant fraction.     

Persistent organochlorine residues in fish and water birds from the Biobio river,Chile

Concentrations of polychlorinated biphenyls (PCBs), DDT and its metabolites, HCH isomers and hexachlorobenzene (HCB) were determined in fish and birds from different locations in the Biobio river basin (central Chile). Samples collected near the mouth of the river contained high concentrations of PCBs, reflecting the massive use of these xenobiotics in the urban and industrial areas of Concepcion and Talcauano. Samples collected in the central part of the basin contained very high concentrations of lindane that coincide with the widespread use of lindane-based pesticides (purified -HCH) in this area. DDT was distributed homogeneously throughout the basin, except at Laguna Icalma, the source of the river in the Andes. Most PCB residues in fish and birds consisted of congeners between penta- and hepta-chlorobiphenyls. In fish, the predominant congeners were the pentachlorobiphenyl 23445 (IUPAC number 118) and the hexachlorobiphenyl 2234455 (PCB-153); in birds 224455 (PCB-180) prevailed.     

Field Study of Wind and Traffic to Test a Street Canyon Pollution Model

In the U.K., local authorities have new duties to review and assess air quality. Dispersion models are important tools in this process. The performance of a street canyon model, AEOLIUS, in calculating carbon monoxide (CO) concentrations in urban areas is discussed. A field experiment was conducted in a busy street canyon in Leek, Staffordshire. Wind speed and direction were measured at three heights adjacent to the street. The canyon's CO concentrations and traffic counts were recorded. Predicted concentrations of CO, calculated using AEOLIUS, were compared with the observed values. The concept of a roof-top wind is discussed, as are the consequences of using wind measurements from outside the town. Choice of wind measurement location and height of the anemometer above the canyon had a pronounced effect on calculating the roof-top wind. Two methods of deriving a street level wind speed from a roof-top wind speed gave results that differ by up to a factor of two. AEOLIUS had variable skill at predicting CO concentrations depending on the roof-top wind direction: possible reasons for this variability are explored. A sensitivity study of the model showed that vehicle emissions have the greatest impact on predicted concentrations. Implications for local air quality management are discussed.     

Biological effect-test systems for the early recognition of unexpected environmental changes

Pre-marketing assessments of chemicals regarding their potential environmental impacts contain numerous sources of error and uncertainties. Practices and methods for the evaluation of environmental risks posed by individual pre-selected agents seem unsuitable for detecting unexpected trends in the environment. This is particularly so in view of the multitude of anthropogenic assaults on the environment and their complex interactions. Therefore, requirements for symptom-oriented biological effect-test systems, bioprobes, capable of reacting sensitively to environmental changes of unknown origin were conceived. Bioprobes designed to detect biological effects should respond to a broad spectrum of anthropogenic chemicals. They are environmental quality measuring devices consisting of cultivated organisms, cells, organelles or biomolecules in combination with recording units. In contrast to traditional biotests for chemical testing, bioprobes are deliberately exposed to selected segments of the environment for certain periods of time. During and after such exposures, changes of defined biological states or process rates—observation elements—are registered.     

Respiratory Suspended Particulate (RSP) Concentration and its Implications to Roadside Workers: A Case Study of Hong Kong

The adsorption behaviour of Diphenylamine (DPAM), napthylamine ( NAM), napthylamine ( NAM)and aniline on pyrolusite and activated carbon has been studied.Pyrolusite shows remarkable sorption capacity for DPAM and NAM as compared to aniline; (the adsorption followed theorder:Activated Carbon: DPAM = NAM > AnilinePyrolusite: DPAM: NAM > NAM> Aniline)The maximum adsorption of NAM occurred in theconcentration range 4–20 g mL^-1 on pyrolusite (95%)and 4–50 g mL^-1 on activated carbon (100%). Theeffect of various doses of activated carbon on the adsorption of NAM confirm Langmuir and Freundlich isotherms where asFreundlich isotherm is obeyed by pyrolusite. The adsorption of NAM on both the absorbents is not affected in presence ofDPAM over a wide range of their initial concentrations (20–60g mL^-1). The desorption studies of NAM onpyrolusite was carried out by batch as well as column processes.Excellent results were obtained when a mixture of n-hexane andisopropanol (91:1) was used as eluent.     

Distribution of Polycyclic Aromatic Hydrocarbons in Aerosols and Dustfall in Macao

Polycyclic aromatic hydrocarbons (PAHs), widespread environmental pollutants, have been measured in aerosols and dustfall in Macao. In this paper, we compare concentration distributions and determine the partitioning of PAHs in aerosols and dustfall for different areas, sampling times and sampling heights. The results demonstrate that the concentrations of PAHs in aerosols and dustfall vary at the different sites and heights. The concentrations of PAHs and most of the individual PAHs in aerosols at night were higher than those in the daytime when using the unit of g/g and lower than those when using the unit of g m^-3. It is shown that the distribution of individual PAHs in aerosols differs significantly from that in dustfall.     

Determination of Endosulfans in Soil/Sediment Samples from Point Mugu, Oxnard, California Using Capillary Gas Chromatography/Mass Selective Detection (GC/MSD)

The extent of contamination by endosulfans in soil samples collected from the Point Mugu watershed near Oxnard, California was determined using capillary gas chromatography/mass selective detection (GC/MSD). The study was designed to detect three organochlorinated pesticides: endosulfan , endosulfan and endosulfan sulfate. Thirteen sets of two soil samples each were taken from various sites in the region. Our results show that the endosulfan levels in these soils range from trace amounts to nearly 30 ppm, with endosulfan being the most abundant and endosulfan sulfate the least. Two sites of the study, Hueneme and Revolon and Farm and Revolon, showed high amounts of endosulfans and , with concentrations between 20 and 30 ppm. The majority of the other sites studied in this research produced concentrations of less than 10 ppm for each of the three endosulfans monitored. At five areas in particular, Pleasant Valley and Creek, Laguna and Creek, Etting and Creek, Road and Creek and Hueneme and Creek, less than 2 ppm or only trace amounts of endosulfans , and sulfate were detected.     

Air pollution and diseases of the respiratory tracts in pre-school children: A transfer function model

The purpose of the present statistical analysis was the assessment of the relation between time series of environmental factors and of frequencies of diseases of the respiratory system in pre-school children. During about one year, daily measurements of air pollutants and climatic variables were taken. During the same period of time two series of medical data were collected: (i) The daily relative number of pre-school children, exhibiting diseases of the respiratory tracts who either came to the outpatients' clinic of the children's hospital or were reported by paediatricians in Basle (ENTRIES). (ii) The daily relative frequency of symptoms of the respiratory tracts observed in a group of randomly selected pre-school children (SYMPTOMS).By means of transfer function models the relation between the two target variables and the explaining variables was analysed. Several practical problems did arise: Choice of the appropriate transformation of the different series, interpretation of the crosscorrelation function using different methods of prewhitening, time splitting and nonstationarity of the crosscorrelation structure. In particular, it was found that after prewhitening the crosscorrelation function between the explanatory series SO₂ and the response series SYMPTOMS changes with time. While during the winter period an instantaneous relation between these two series (and to a lesser extent between NO₂ and SYMPTOMS) was identified, no such relation was found for the other seasons.     

Ozone biomonitoring in Northern Italy

This report presents the results of an ozone monitoring experience performed with tobacco indicator plants (Nicotiana tabacum L. cv. Bel-W3). These bioindicators were exposed to ambient air in 23 sites in Northern Italy from 27 April 1987 to 21 October 1987. Typical ozone-induced leaf necrosis was observed in every site. The percentage increase in injured leaf area was estimated weekly and a Leaf Injury Index (LII) was calculated. The weekly series of LIIs were statistically inspected for spatial and temporal relationships. Sample correlation coefficients were statistically significant for almost every possible pair of sites. The time series properties of ten series of LIIs with no missing data were analyzed using Box-Jenkins models. An autoregressive first order model, or AR(1), was selected to remove the autocorrelation from these series. Linear correlation coefficients between prewhitened (i.e. from which autocorrelation had been removed) pairs of LII series were statistically significant. Hence synchronous variations in leaf necrosis could only be related to the regional diffusion of tropospheric ozone.Work carried out as part of the research programme: ENEL's contribution to the knowledge of important environmental issues, Research line; Effects of atmospheric pollution on the land.     

An evaluation of benthic macroinvertebrate biomass methodology

This study shows that biological assessments of water quality status using biomass estimates of wet, dry, and ash-free dry weights and counts of individual organisms from a small, headwater stream in southwestern Ohio provide essentially similar results concerning the impact of a sewage treatment plant discharge. Of the indices of biotic status for the stream segment employed for data evaluation; Diversity Index (D), Community Diversity Index (d), Trophic Condition Index (TCI), and Empirical Biotic Index (EBI), the latter two provided evaluations most consistent with benchmark water chemistry and physics information concerning the trophic status of the stream. In addition, the percent composition of macro-invertebrate taxa by pollutional category; clean water, facultative, and pollution tolerant, as ascribed using TCI and EBI ranges for individual taxa collected in combination of Ekman grab, rock-filled basket sampler and drift net samples, proves adequate for interpretation of biotic status.     

Correlation between environmental parameters and leaf injury in Nicotiana tabacum L. cv. ‘Bel-W 3’

Tobacco plants (Nicotiana tabacum L. cv. Bel-W3) were exposed to ambient air for 25 weeks during the 1987 growing season next to an air pollution monitoring station in Brera (Milan, Italy). The research objective was to study the influence of selected environmental parameters on leaf damage in this plant, which is widely used as an ozone indicator. A multiple linear correlation model was estimated between leaf damage and available meteorological and air pollution data. Leaf injury was positively correlated with ozone integrated exposure and temperature, but negatively with vapour pressure deficit. A linear correlation model was used to estimate ozone integrated exposure from the leaf injury indexWork carried out as part of the research programme: ENEL's contribution to the knowledge of important environmental issues, research line: Effects of atmospheric pollution on the land.     

A FRAMEWORK FOR THE ULTIMATE ENVIRONMENTAL INDEX – Putting Atmospheric Change Into Context With Sustainability

Assessing the major atmospheric issues – acidic deposition, climatechange, ozone depletion, smog, hazardous airpollutants and suspended particulate matter – together rather than individually provides many advantages. But to be successful, this integration requires a common method for relating theseissues to one another. This is a scientific question.In order to successfully resolve the atmospheric issues (a policy question) requires communication of the relevant science to non-scientists in plain language. Non-scientists need to be part of the development of the structure of the communications vehicle. The objective for multi-issueassessment, and thus for the development of an index to trackthe state of the environment in an integrated way, is of courserelated to the desire to achieve environmentally sustainable development.Sustainability can be represented by a 3-legged stool and is an aptsymbol of the struggle of Canadians to balance their ecological,economic and social needs. Although the environment is the basisof all life, humankind has created society and has defined how thatsociety will function (the economy). The three legs of the stool(ecosystem, economy, society) represent the three parts of thesustainability balance. The seat of the stool represents thegovernance process and the three legs are deeply embedded in thisgovernance process because it is the governance which ensures thestability of the system over time. The challenge then is to measure the stability of the stool in a waywhich all can understand. This measure of sustainability must respondto individual and collective actions which improve or degrade the environment. This paper presents such a framework for a sustainability index andoutlines the next steps that need to be taken.The framework starts from the premise that ecosystem, economy andsociety are equal parts of sustainability. Ecosystem indices arerepresentative measures of the state of the environment while economicindices are representative measures of the state of the economy. Socialindices in some way have to measure the state of society. The trick,for a successful sustainability index, will be to ensure that the importantaspects of the ecosystem, the economy and society, are included. The overall index must berelatively stable but must be responsive to changes.     

Monitoring the biotic aspects of our environment as a policy instrument

As all environmental programs also programs monitoring the biotic aspects of our environment (dealt with in this article) should contribute to a more effective and efficient environmental policy. These programs have to function therefore (as no other type of environmental information does, according to the authors) as cheap and efficient early warning and early control systems, providing decision makers with important and reliable monitoring results.How these monitoring programs should function in the decision making process is illustrated in abstract in this article by a simple control system with feedback (as shown in Figures 1, 2 and 3).The monitoring programs dealt with in this article should enable us to detect and forecast changes in the most important biotic aspects of our environment and-by continuous monitoring-to control whether the use of policy instruments has been effective or not in averting or diminishing unwanted changes (problems).Two options of decision makers with respect to monitoring results are shown (either to disregard unwanted changes as a problem or to accept these changes as a problem and to do something about them). To contribute to an effective and efficient environmental policy monitoring results therefore have to be important and reliable enough to react upon.The question is raised which biotic aspects in our environment are (or have to be considered as) important (because of their own value, as indicators and/or as biotic conditions) and how reliable monitoring results can (have to) be obtained.It is discussed how environmentalists could try to make it more difficult for decision makers to duck the problems (by monitoring only important aspects and by using only perfectly clear targets and standards) and how they could try at the same time to make it easier for them to take action (by setting up integrated environmental monitoring programs in order to find out how desired and undesired changes can be influenced). The role of active publicity is stressed in this connection.     

Application of remote sensing to exposure monitoring

Although exposure assessments cannot be completed remotely, remote sensing techniques provide an invaluable adjunct in exposure monitoring programs. Exposure can be defined as the summation over time, in all media, of the amount of a pollutant available at the exchange boundaries of the receptor during a specified period. This paper describes a few remote monitoring techniques that provide direct measurement input into an exposure assessment and several that furnish quantitative or qualitative information leading to decisions regarding how to monitor, such that the source-exposure-dose relationships can be fully defined. Two general classes of remote sensing systems are included in this discussion-passive and active. Passive systems depend on a measurement of the energy reflected or emitted by a target and active systems use an energy source, e.g., a laser to perform the environmental interrogation. Airborne as well as ground-based remote monitoring measurements or systems are also considered in this paper.     

A Screening Procedure for Identifying Acid-Sensitive Lakes from Catchment Characteristics

Monitoring of Wilderness lakes for potential acidification requires information on lake sensitivity to acidification. Catchment properties can be used to estimate the acid neutralizing capacity (ANC) of lakes. Conceptual and general linear models were developed to predict the ANC of lakes in high-elevation (2170 m) Wilderness Areas in Californias Sierra Nevada mountains. Catchment-to-lake area ratio, lake perimeter-to-area ratio, bedrock lithology, vegetation cover, and lake headwater location are significant variables explaining ANC. The general linear models were validated against independently collected water chemistry data and were used as part of a first stage screen to identify Wilderness lakes with low ANC. Expanded monitoring of atmospheric deposition is essential for improving the predictability of lake ANC.