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Investigators used a Lioy-Weisel-Wainman sampler to analyze the chromium content in house-dust samples obtained from households near chromium waste sites in Hudson County, New Jersey. Chromium concentrations in dust ([micro]g/g)--indicative of nonbackground source contributions--were significantly higher in Jersey City homes than in control homes outside of Hudson County (228 and 111 [micro]g/g, respectively; p [is less than] .001). Chromium dust loadings on surfaces (ng/[cm.sup.2]), representing the amount of chromium available for contact and a direct measure of exposure potential, were also higher in Jersey City homes than in control homes (31 ng/[cm.sup.2] and 14 ng/[cm.sup.2], respectively; p = .008). Near some of the sites, investigators found elevated chromium dust loads more frequently in homes occupied by at least one household member who had elevated urine chromium, as determined in a separate screening project, than in homes occupied by members whose urine chromium was not elevated. Individuals with elevated urine chromium levels were found less frequently in homes in which good housekeeping practices were evident than in homes absent such practices., DURING THE PAST 10 Y, investigators have identified more than 160 chromate production waste sites within Hudson County, New Jersey--particularly within Jersey City.[1] These sites are distributed throughout the community [...]

. It is thought that gaseous ammonia in breath neutralizes acidic air pollution and thereby potentially mitigates the pulmonary effects of pollution. The efficacy of breath ammonia depletion methods reported in recent acid aerosol exposure-health response studies was investigated. Fourteen subjects (21 to 54 y of age) performed one or more of the following hygiene maneuvers: (a) acidic oral rinse (pH 2.5); (b) tooth brushing, followed by acidic oral rinse; (c) tooth brushing, followed by distilled water rinse; and (d) distilled water rinse. Initial ammonia levels ranged from 120 to 1 280 ppb (147-1 570 [micro]g/[m.sup.3]). Acidic rinsing resulted in an immediate 90% reduction in exhaled ammonia in all subjects, and a return to 50% of baseline levels occurred within 1 h. Depletion that resulted from tooth brushing or distilled water alone was not significant. It was concluded that acidic oral rinsing is an effective method of reducing airway ammonia, but repeated oral rinsing may be required to maintain consistent, low-breath-ammonia conditions during acid aerosol exposure studies., AMBIENT AMMONIA neutralizes sulfuric acid aerosols, and its neutralization products--([NH.sub.4])[2S0.sub.4] and [NH.sub.4][HSO.sub.4]--are thought to have significantly less irritant potency than [H.sup.2.SO.sup.4].[1,2] The relative acidity of acid aerosols has been associated [...]

During the winter of 1988-1989, parents of 2,789 elementary-school students completed standardized questionnaires. The students were 5-14 y of age and were from three urban districts and one suburban district of three large Chinese cities. The 4-y average ambient levels of total suspended particles in the three cities differed greatly during the period 1985-1988: Lanzhou, 1,067 [micro]g/[m.sup.3]; urban Wuhan, 406 [micro]g/[m.sup.3]; Guangzhou, 296 [micro]g/[m.sup.3]; and suburban Wuhan, 191 [micro]g/[m.sup.3]. The authors constructed unconditional logistic-regression models to calculate odds ratios and 95% confidence intervals for prevalences of several respiratory symptoms and illnesses, adjusted for district, use of coal in the home, and parental smoking status. There was a positive and significant association between total suspended particle levels and the adjusted odds ratios for cough, phlegm, hospitalization for diseases, and pneumonia. This association was derived from only the 1,784 urban children and, therefore, the authors were unable to extrapolate it to the suburban children. The results also indicated that parental smoking status was associated with cough and phlegm, and use of coal in the home was associated only with cough prevalence ([Alpha] - 0.05)., MANY REPORTS regarding the effects of indoor and outdoor air pollution on children's respiratory health have appeared in the scientific literature, including studies conducted in the People's Republic of China [...]

This study provides a quantitative assessment of inhalation exposure and deposited aerosol dose in the 14 nm to 20 μm particle size range based on the aerosol measurements conducted during realistic usage simulation of five nanotechnology-based and five regular spray products matching the nano-products by purpose of application. The products were also examined using transmission electron microscopy. In seven out of ten sprays, the highest inhalation exposure was observed for the coarse (2.5–10 μm) particles while being minimal or below the detection limit for the remaining three sprays. Nanosized aerosol particles (14–100 nm) were released, which resulted in low but measurable inhalation exposures from all of the investigated consumer sprays. Eight out of ten products produced high total deposited aerosol doses on the order of 101–103ng kg−1bw per application, ~85–88% of which were in the head airways, only <10% in the alveolar region and <8% in the tracheobronchial region. One nano and one regular spray produced substantially lower total deposited doses (by 2–4 orders of magnitude less), only ~52–64% of which were in the head while ~29–40% in the alveolar region. The electron microscopy data showed nanosized objects in some products not labeled as nanotechnology-based and conversely did not find nano-objects in some nano-sprays. We found no correlation between nano-object presence and abundance as per the electron microscopy data and the determined inhalation exposures and deposited doses. The findings of this study and the reported quantitative exposure data will be valuable for the manufacturers of nanotechnology-based consumer sprays to minimize inhalation exposure from their products, as well as for the regulators focusing on protecting the public health.

The role of children's activities in leading to pesticide exposure was evaluated by comparing pesticide loadings on the hands of children with the activities of the same children observed over a 4-h period. In all, 10 children ranging in age from 24 to 55 months were videotaped on the second day following a routine professional crack and crevice chlorpyrifos application in their homes. Before and following the video session, the children's hands were rinsed in isopropyl alcohol. Thus, only the chlorpyrifos that accumulated on and remained on the child's hands during the videotaping were removed for analysis after the videotaping session. The rinsate was analyzed for chlorpyrifos. The children's behaviors were quantified using virtual tracking device and the frequency and duration of behaviors, the hourly rate of behaviors, and the locations in which behaviors occurred were compared to hand loadings of pesticides. Pesticide hand loadings obtained following the videotaping sessions were associated with pesticide levels on surfaces and toys, but not with air levels. Pesticide loadings obtained following the videotaping sessions were also associated with frequencies, durations, and hourly rates of contact with bottles, and object-to-mouth behaviors, as well as contact duration with upholstered/textured surfaces. The hand loadings were also associated with the number of locations where the children exhibited object-to-mouth behavior and with children's use of house space during the videotaping sessions.Journal of Exposure Analysis and Environmental Epidemiology (2005) 15, 81–88. doi:10.1038/sj.jea.7500348 Published online 24 March 2004

The explosion and collapse of the World Trade Center (WTC) was a catastrophic event that produced an aerosol impacting many residents, workers, and commuters after September 11, 2001. In all, 12 bulk samples of the settled dust were collected at indoor locations surrounding the epicenter of the disaster, including one sample from a residence that had been cleansed and was once again occupied. Additionally, one sample was collected from just outside a fifth story window on the sill. These samples were analyzed for many components, including inorganic and organic constituents as well as morphology of the various particles. The results of the analyses for persistent organic pollutants on dusts that settled at indoor locations are described herein, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and select organo-chlorine pesticides. The Σ86-PCB concentrations, comprising less than one part per million by mass of the bulk in the two samples analyzed, indicated that PCBs were of limited significance in the dust that settled at indoor locations across lower Manhattan. Likewise, organo-chlorine pesticides, Hexachlorobenzene, Heptachlor, 4,4′-DDE, 2,4′-DDT, 4,4′-DDT and Mirex were found at even lower concentrations in the bulk samples. Conversely, Σ37-PAHs comprised up to 0.04% (<0.005–0.036%) by mass of the bulk indoor dust in the 11 WTC impacted bulk indoor samples. Analysis of one sample of indoor dusts collected from a vacuum cleaner of a rehabilitated home shows markedly lower PAH concentrations (<0.0005 mass%), as well as differing relative contributions for individual compounds. In addition to similar concentrations, comparison of PAH concentration patterns (i.e. chemical fingerprints) shows that dusts that settled indoors are chemically similar to previously measured WTC dusts found at outdoor locations and that these PAH analyses may be used in identifying dusts of WTC origin at indoor locations, along with ascertaining further needs for cleaning.Journal of Exposure Analysis and Environmental Epidemiology (2004) 14, 164–172. doi:10.1038/sj.jea.7500310

The objective of this study was to compare the driving habits and vehicle maintenance patterns of individuals who report symptoms when exposed to methyl tertiary-butyl ether (MTBE) and those who are asymptomatic when exposed to the oxygenate. Participants were healthy volunteers (CON) and self-reported MTBE-sensitive individuals (SRS) who participated in a controlled exposure study of MTBE in gasoline. A questionnaire was developed to gather information about each participant's automobile usage, engine maintenance habits and fueling and driving patterns. Results showed that the individuals who had self-reported heightened sensitivity to the oxygenate drove their vehicles more often and fueled their vehicles more frequently than asymptomatic individuals. In addition, the self-reported symptomatic individuals in this study were shown to be more likely to drive vehicles with some form of body damage and carbureted engines.Journal of Exposure Analysis and Environmental Epidemiology (2001) 11, 79–85. 10.1038/sj.jea.7500143

Children have been one of the least-studied populations for estimating environmental exposure, even though they are cited as a sensitive subgroup for diseases derived from environmental exposure. This trend appears to be changing as more studies are conducted with children as subjects. It consequently becomes increasingly important to gather and use observational data in all phases of the study. Observational data are the key for both defining the pathway of exposure and for assessing effectiveness of the data-collection protocols. Obtaining quality data from a study involving children requires: efficient use of observational data, collection of meaningful personal and microenvironmental samples, linkage of observational data to the collected samples, and personnel trained to work with children using pilot-tested protocols. Although all of these help to ensure the quality of the data, the utility of the data is often determined by observational feedback from those who collected it. Laboratory-derived protocols should be living documents and observations from the field should be used to modify the data-collection methods when practical.Journal of Exposure Analysis and Environmental Epidemiology (2000) 10, 695–702. 10.1038/sj.jea.7500127

The purpose of this manuscript is to describe the practical strategies developed for the implementation of the Minnesota Children's Pesticide Exposure Study (MNCPES), which is one of the first probability-based samples of multi-pathway and multi-pesticide exposures in children. The primary objective of MNCPES was to characterize children's exposure to selected pesticides through a combination of questionnaires, personal exposure measurements (i.e., air, duplicate diet, hand rinse), and complementary monitoring of biological samples (i.e., pesticide metabolites in urine), environmental samples (i.e., residential indoor/outdoor air, drinking water, dust on residential surfaces, soil), and children's activity patterns. A cross-sectional design employing a stratified random sample was used to identify homes with age-eligible children and screen residences to facilitate oversampling of households with higher potential exposures. Numerous techniques were employed in the study, including in-person contact by locally based interviewers, brief and highly focused home visits, graduated subject incentives, and training of parents and children to assist in sample collection. It is not feasible to quantify increases in rates of subject recruitment, retention, or compliance that resulted from the techniques employed in this study. Nevertheless, results indicate that the total package of implemented procedures was instrumental in obtaining a high percentage of valid samples for targeted households and environmental media.Journal of Exposure Analysis and Environmental Epidemiology (2000) 10, 650–661. 10.1038/sj.jea.7500126

Although children are exposed to a variety of environmental hazards, including pesticides, there is a scarcity of information available to estimate exposures realistically. This article reports on one of the first attempts to measure multi-pathway pesticide exposures in a population-based sample of urban and non-urban children. A design strategy was developed to assess multi-pathway pesticide exposures in children using personal exposure measurements in combination with complimentary measurements of biological markers of exposure, concentrations in relevant environmental media, and time spent in important microenvironments and participating in exposure-related activities. Sample collection and analysis emphasized measurement of three insecticides (i.e., chlorpyrifos, diazinon, and malathion) and one herbicide (i.e., atrazine). These compounds were selected because of their frequent use, presence in multiple environmental media, expected population exposures, and related hazard/toxicity. The study was conducted during the summer of 1997 in Minnesota and involved a stratified sample of households with children ages 3–12 years. Participants resided in either (a) the cities of Minneapolis and St. Paul (urban households), or (b) Rice and Goodhue Counties just south of the metropolitan area (non-urban households). Results from a residential inventory documenting storage and use of products containing the target pesticides were used to preferentially select households where children were likely to have higher exposures. The study successfully obtained pesticide exposure data for 102 children, including measurements of personal exposures (air, hand rinse, duplicate diet), environmental concentrations (residential indoor/outdoor air, drinking water, residential surfaces, soil), activity patterns (obtained by questionnaire, diary, videotaping), and internal dose (metabolites in urine).Journal of Exposure Analysis and Environmental Epidemiology (2000) 10, 145–158. 10.1038/sj.jea.7500080

ABSTRACTThe issue of fine particle (PM25) exposures and their potential health effects is a focus of scientific research because of the recently promulgated National Ambient Air Quality Standard for PM2 5. Before final implementation, the health and exposure basis for the standard will be reviewed by the U.S. Environmental Protection Agency within the next five years. As part of this process, it is necessary to understand total particle exposure issues and to determine the relative importance of the origin of PM2 5exposure in various micro-environments. The results presented in this study examine emissions of fine particles from a previously uncharacterized indoor source: the residential vacuum cleaner. Eleven standard vacuum cleaners were tested for the emission rate of fine particles by their individual motors and for their efficiency in collecting laboratory-generated fine particles. An aerosol generator was used to introduce fine potassium chloride (KC1) particles into the vacuum cleaner inlet for the collection efficiency tests. Measurements of the motor emissions, which include carbon, and the KCl aerosol were made using a continuous HIAC/Royco 5130A light-scattering particle detector. All tests were conducted in a metal chamber specifically designed to completely contain the vacuum cleaner and operate it in a stationary position. For the tested vacuum cleaners, fine particle motor emissions ranged from 9.6 x 104to 3.34 x 108particles/min, which were estimated to be 0.028 to 176 mg/min for mass emissions, respectively. The vast majority of particles released were in the range of 0.3-0.5 mm in diameter. The lowest particle emission rate was obtained for a vacuum cleaner that had a high efficiency (HEPA) filter placed after the vacuum cleaner bag and the motor within a sealed exhaust system. This vacuum cleaner removed the KC1particles that escaped the vacuum cleaner bag and the particles emitted by the motor. Results obtained for the KC1 collection efficiency tests show >99% of the fine particles were captured by the two vacuum cleaners that used a HEPA filter. A series of tests conducted on two vacuum cleaners found that the motors also emitted ultra-fine particles above 0.01 mm in diameter at rates of greater than 108ultra-fine particles/CF of air. The model that had the best collection efficiency for fine particles also reduced the ultra-fine particle emissions by a factor of 1 x 103.

The time/activity diary developed for use in the National Human Exposure Assessment Survey (NHEXAS) was completed by 249 participants in the Research Triangle Institute/Environmental and Occupational Health Sciences Institute (RTI/EOHSI) NHEXAS population-based pilot project conducted in the upper Midwest (EPA Region 5). The majority of participants successfully completed the diary during the 6-day study period. Participant responses showed internal consistency between related questions within the diary and between instruments used within the study. Comparison of response rates with the National Human Activity Pattern Survey, a nationwide population-based study, found consistent results when the same questions were used in both studies. Several questions identified age-specific activities. The value of the 6-day diary over 1-day surveys was apparent in discriminating between episodic and regularly conducted activities and in identifying subpopulations whose behavior may contribute to exposure to environmental pollutants.Journal of Exposure Analysis and Environmental Epidemiology (1999) 9, 414–426. 10.1038/sj.jea.7500052

Indirect sampling techniques to estimate dermal exposure to pesticides on housedust-laden indoor surfaces should demonstrate collection efficiencies, for both particles and pesticide residues, which are similar to those that would adhere to the human skin. A spring-loaded press sampler has been developed that approximated the particle- and pesticide-collection efficiencies of a hand press of a human participant. Particle-collection efficiencies for the hand press and EL sampler, using housedust sieved to <250 µm in diameter, indicated that both sampling techniques collected similar particle fractions over the range of particle sizes. Pesticide-collection efficiencies measured on the participants hand (seven paired tests) were 42±7% atrazine, 29±8% diazinon, 43±8% malathion and 21±5% chlorpyrifos. The EL sampler collected 35±5%, 31±3%, 32±5% and 18±3% respectively. The collection efficiencies of the two sampling techniques were highly correlated for atrazine, diazinon, and chlorpyrifos (correlation coefficient=0.840, 0.815, and 0.706), but not for malathion (correlation coefficient=0.086).Journal of Exposure Analysis and Environmental Epidemiology (1999) 9, 521–529. 10.1038/sj.jea.7500048

A videotaping methodology has been developed for use in quantifying the types and frequencies of children's hand and mouthing activities that could lead to exposure to environmental pollutants via dermal and ingestion pathways. Twenty children in day care, ages 3–6 years and 10 children in residences, ages 2–5 years, were videotaped during their waking hours for 1 day. Parents of each child completed questionnaires for the purpose of evaluating the accuracy of parental reports of hand-to-mouth rates. Videotapes were translated as quantifiable activities by two trained observers whose reporting reliability was checked throughout the investigation. Results determined that reliability of the videotaping method was very good, even over a year post-training. From videotape data, the average hand-to-mouth frequency rate was determined to be 9.5 contacts/h. These values are considerably higher than the current default value of 1.56 contacts/h under consideration by the EPA.Journal of Exposure Analysis and Environmental Epidemiology (1999) 9, 513–520. 10.1038/sj.jea.7500047

Comparability of dust lead measurements has been a difficult problem due to different sampling and analysis techniques. This paper compares two dust sampling techniques, the U.S. Department of Housing and Urban Development (HUD) dust wipe method and the Lioy, Wainman, Weisel (LWW) sampler. The HUD method specifies using a moist towelette to pick up as much dust as possible in a specified area and estimates total lead loading. The LWW sampler collects the dust on preweighed wetted filter media, and provides greater standardization of the sampling path and pressure applied. LWW samples were analyzed using inductively coupled plasma mass spectronomy (no samples below minimum detection limit), while HUD samples were analyzed using flame atomic absorption (32% of samples below minimum detection limit). A bootstrapping technique was used in the analysis to contend with those HUD samples below the minimum detection limit. Mixed model equations were generated to predict HUD values from LWW results, and to examine the effects of sampling location, time, and method. The results indicate that the two samplers performed similarly under field conditions, although the LWW sampler produced consistently lower lead loading estimates. LWW values that predicted HUD lead clearance values of 100 μg/ft2for floors and 500 μg/ft2for window sills were 72 μg/ft2and 275 μg/ft2, respectively. To examine internal reproducibility, duplicate samples were taken using both the HUD and LWW methods. Correlation results within paired samples indicated a statistically significantly higher (p<0.001) internal reproducibility for lead loading, for the LWW sampler (r=0.87), than for the HUD method (r=0.71). Some of the differences appeared to be related to the analytical methods.Journal of Exposure Analysis and Environmental Epidemiology (1999) 9, 106–112. 10.1038/sj.jea.7500006

Identifies the general methods used to complete measurements of human exposures. General concepts for using exposure analysis techniques; General issues confronting development of microenvironmental monitors or air pollutants; Incidence of disease using exposure data.

A study was conducted to investigate the effect of sampling duration upon the concentration of particulate organic matter (POM) collected on glass fiber filters. Samples of total suspended particulate matter were simultaneously collected over three sampling periods: seven days (1 weekly sample), twenty-four hours (13 daily samples), and six hours (4/day for 13 days). Each collected filter sample was extracted sequentially with solvents of increasing polarity, cyclohexane, dichloromethane, and acetone, respectively. Higher concentrations of cyclohexane-soluble organic matter were observed with longer sampling periods for these simultaneously collected samples. In contrast, concentrations of dichloromethane-soluble fraction were lower as the duration of sampling increased. The concentrations of the acetone-soluble fractions showed no significant dependence on sampling duration, within the experimental uncertainties.

Ambient sulfates, total suspended particulates (TSP), and ozone data were collected in rural areas of New York and New Jersey as part of a study conducted jointly by the New York State Department of Environmental Conservation and the Interstate Sanitation Commission during July and August 1975. Relationships between these contaminants and various meteorological systems were examined. The sulfate and TSP data were obtained from 24-hour integrated high volume samples obtained on a daily basis at seven rural sites with the emphasis in this paper being on two sites: Whiteface Mountain, N.Y., and High Point, N.J. The sulfate concentrations were found to be highest during four distinct periods which were generally defined by anticyclonic stagnation and/or return flow of maritime tropical air. The highest values recorded at Whiteface Mountain and High Point were 24 μg/m3 and 20 μg/m3, respectively, in the period from July 21 through 25. During the other three periods, a maximum of at least 15 μg/m3 was observed at one or both sites. Coincidence of the high level periods at the two sites separated by approximately 200 miles and at five other rural New York State sites during most of the study is a strong indication of long-range transport. -The maximum sulfate concentration recorded during the study was 38 μg/m3 at Schoharie, N.Y.The SO4/TSP ratio (maximum 0.53) at High Point and Whiteface Mountain was increased, though nonuniformily, with higher TSP during the episode periods. Ozone concentrations at High Point were increased simultaneously with sulfates, as in previous observations at Whiteface Mountain1 which suggests it is either an important reactant in the formation of sulfates or these contaminants are concommitant in photochemical processes and/or summertime anticyclonic systems.

As part of the Total Human Exposure to Environmental Substances (THEES) Study, weekly composites of in-home prepared meals from approximately ten individuals for each of three two-week "campaigns" were analyzed for benzo[a]pyrene content. In addition, daily composites for four individuals during the third "campaign" (THEES III) were analyzed. The analytical technique employs alcoholic KOH saponification of food samples, extraction, column chromatography on florisil and TLC chromatography on 20% acetylated cellulose and detection/quantitation using fluorescence. Limit of detection and sample recovery data are presented in addition to the meal data. B[a]P levels in food are highly variable but are frequently high enough to make contributions which exceed inhalation exposure.

Indoor and outdoor air measurements of PM-10 (particulate mass dp < 10 μm) and its benzo (a)pyrene (Bap) content were made daily in 13 residences and 5 nearby sites during one or more of three 14-day periods (Winters 1987 and 1988, and Fall 1988). These are a population of older homes (60+ years) adjacent to a gray-iron foundry. Winter BaP values were ∼ 10 × higher than fall values. Indoor BaP sources in several homes (e.g., cooking, cigarette smoke, a coal stove) led to contaminant levels higher than the ambient concentrations. However, in homes without strong sources, concentrations were very close to outdoor levels. Periods of elevated ambient pollution were readily discernible in the record of virtually all homes. Correlations for indoor-outdoor concentrations (PM-10 and BaP) were statistically significant (p < 0.01) in the majority of homes.Higher BaP concentrations were associated with periods of lower temperatures. There were high degrees of correlation for BaP and PM-10 among outdoor sites. The fraction of BaP in ambient PM-10 (mass ratio BaP/PM-10) was found to be a fairly stable parameter for each season. These factors suggest the predominance of a spatially diffuse source of BaP in the community, such as space heating combustion. The higher BaP/PM-10 ratios were identifiable as an index of indoor sources.

The approach and conclusions of the ATEOS project will be examined with an emphasis on future design considerations and strategies to address and reduce exposures. The ATEOS was a five year project that conducted field sampling in the summer and winter for the years 1981 through 1983. Eighty-five outdoor air pollutants were measured including the composition of inhalable particulate mass, and volatile organic compounds. The particulate mass components measured were the non-polar through polar organic fractions, polycyclic aromatic hydrocarbons, SO-24, trace elements and alkylating agents. From the numerous volatile organic compounds present in the atmosphere measurements were made of 10 chlorinated compounds, the automobile by products, e.g., benzene, o and p xylene, and 13 solvents. Other measurements included local meteorology. Besides the wealth of variables an important component of the study was the selection of the outdoor sites. The approach was to choose specific types of population — industrial-commercial locales with increasing (or decreasing) complexity. The sites were located in the New Jersey urban centers of Newark, Elizabeth and Camden, and a rural setting in Ringwood, N. J. The Newark site was the most complex industrial-commercial-residential interface followed in decreasing order by Elizabeth, Camden and Ring-wood. The manuscript will emphasize the characteristics of the measured variables in relation to the differences in the neighborhoods surrounding each site. Summary information on source — receptor modeling, pollution accumulation processes, episode analyses, and exposure assessment studies will be presented. These will be all evaluated with respect to future study design questions, including monitoring frequency, epidemiological exposure assessments and indoor air pollution.

The science of exposure assessment has been expanding both its theoretical and experimental bases over the past two years. Recent theoretical work published by the authors in the Journal of Exposure Analysis and Environmental Epidemiology (Volume 4, Number 3, 1994) has defined a multistep process to couple measurement data with mathematical models of exposure and dose. The present manuscript discusses the need for improving the measurement of exposure in order to reduce uncertainties in the potential risk and, eventually, the occurrences of health outcomes in the community environment. The discussion focuses on hazardous waste sites and how improving or routinely introducing exposure measurements to the remedial investigation can lead to a better understanding of how the potential population can get exposed via single or multiple activities. This information can help to better understand the need for specific remediation actions and selection of the types of models that can be used to predict exposure for a large population and to estimate the reduction in postremediation exposure for a local population (National Research Council, 1991).

Urinary banzo[a]pyrene (BaP) metabolite levels were compared to human environmental exposure to BaP through inhalation and dietary ingestion to assess the predictive validity of the exposure biomarker. These measurements were made for 14 adult volunteers over 14 consecutive days, once during summer/fall, again during winter periods. Based on personal air monitoring, median potential inhalation doses of 11.0 and 2.3 ng/day were estimated for the winter and summer/fall studies, respectively. A median potential ingested dose of 176 ng/day, estimated from “duplicate plate” sampling, exceeded inhalation by 6-and 122-fold for the winter and summer/fall studies, respectively. “Total” urinary BaP metabolites were measured using a published “reverse metabolism” (BaP) method of analysis. Median rates of urinary BaP metabolite elimination for the winter and summer/fall studies were 121 and 129 ng/day, respectively. The changes in inhaled and ingested potential doses were regressed on the change in urinary metabolite elimination from week 1 to week 2 to test the predictive validity of the biomarker measurement. The regression was statistically significant (r = 0.620, p = 0.015, n = 25) when body weight was included and two extreme values were removed. Consistent with the exposure measurements showing diet as the dominant route of exposure, most of the variation in urinary metabolite elimination was explained by the ingested dose. It is concluded that the measurement of urinary BaP by “reverse metabolism” is qualitative and of marginal predictive validity as an exposure biomarker due to the method's low recoveries and the large unexplained variance.

Investigators used a Lioy-Weisel-Wainman sampler to analyze the chromium content in house-dust samples obtained from households near chromium waste sites in Hudson County, New Jersey. Chromium concentrations in dust (μg/g)—indicative of nonbackground source contributions—were significantly higher in Jersey City homes than in control homes outside of Hudson County (228 and 111 μg/g, respectively; p < .001). Chromium dust loadings on surfaces (ng/cm2), representing the amount of chromium available for contact and a direct measure of exposure potential, were also higher in Jersey City homes than in control homes (31 ng/cm2 and 14 ng/cm2, respectively; p = .008). Near some of the sites, investigators found elevated chromium dust loads more frequently in homes occupied by at least one household member who had elevated urine chromium, as determined in a separate screening project, than in homes occupied by members whose urine chromium was not elevated. Individuals with elevated urine chromium levels were found less frequently in homes in which good housekeeping practices were evident than in homes absent such practices.

The MS&T personal impactor is designed to provide a particle size cut (d50%) of 10 μm in aerodynamic diameter (PM-10) at a flow rate of 4 L/min. Data are presented that verify the designed particulate mass cut specifications of this impactor for personal sampling. These data are derived from three different analyses', laboratory calibration, intersampler comparison, and field application. Laboratory calibration using monodispersed liquid aerosol shows a sharp 10-μm particle cut size.The performance of the personal impactor was tested using ambient and combustion-generated aerosols. Established PM-10 samplers (the Sierra/Andersen dichotomous and the MS&T indoor air sampler impactor) were run side by side with the personal impactor. The intra- and intersampler vari-abilities in PM-10 measurements were evaluated. Results showed good precision among personal impactors (CV = 3.2%). The PM-10 sampled by the personal impactor was found to be highly correlated with measurements made with the indoor air sampler impactor (r2 = 0.99) and the dichotomous sampler (r1 = 0.97).The impactor was subsequently employed for personal air sampling in the Total Human Environmental Exposure Study (THEES). The THEES sampling protocol entailed 24-hour sampling during a 14-day study interval. THEES field measurements included indoor, outdoor, and personal PM-10 samples. The personal impactor measurements for 13 participants were predicted by a time-weighted exposure model using indoor and outdoor PM-10 and specific activity variables (p < 0.01).

Chromate slag is found mixed with soil at several sites in New Jersey. Previous analyses of the contaminated soil were limited to particle sizes > 30 μm. This study focuses on the inspirable, thoracic, and respirable particles that would enter the human respiratory tract, should the contaminated soil become airborne. This article discusses the soil-sampling procedure used at a slag-contaminated site and a site with visible hexavalent chromium crystals. In addition, the drying and sieving procedures and the techniques needed to resuspend the contaminated dust in a sealed chamber are described for aerodynamic size fractionation (30, 10, and 2.5 μm). The resuspended dust was collected on filters and analyzed for 38 elements by x-ray fluorescence (XRF). Wet chemistry techniques were used to measure total extractable and hexavalent chromium. It was found that 1.6% of the slag had a particle aerodynamic diameter (at 50% cut-point) d50 = 30 μm, of that 1.1% was d50 = 10 μm and 0.26% was d50 = 2.5 μm. Total chromium and lead concentrations above 1000 ppm were found in all particle sizes. Comparison of the total chromium results derived for two analytical techniques showed that the total chromium, in the contaminated soil exists in soluble and nonsoluble forms, and that the nitric acid method extracts ∼ 30% of the total chromium present in the slag measured by XRF. Hexavalent chromium concentrations > 1000 ppm were found in the contaminated soil that contained visible chromium blooms, and were 1800, 1700, and 1200 ppm for the inhalable, thoracic, and respirable size ranges, respectively.

Data obtained in a study of the deposition of monodisperse particles in replicate casts of the human upper bronchial tree were used to develop an empirical model for prediction of bronchial deposition under both constant and cyclic inspiratory flow conditions. The model incorporates specific morphometric factors which affect deposition.

As a result of the 1975 Moodus Conference, a task force was established to analyze the ozone data from the 19 Moodus states and to assess the importance of ozone transport across the Midwestern and Northeastern United States. Data from daily ozone maps, aerial ozone measurements, and trajectory analysis are used in this paper to describe the typical summertime ozone episode in the Moodus study area. The results indicate that ozone concentrations in a high pressure system as it moves out of Canada into the Midwest are typically 30-50 ppb. Higher concentrations first develop over the areas of high anthropogenic percursor emissions. As the high pressure moves eastward, the areas of high ozone increase in size and concentration and eventually merge together. Verticle ozone profiles conducted on consecutive days and nights suggest an ozone half-life of 46.8 h above the nocturnal inversion layer. Using the corresponding dark phase rate of ozone decay in conjunction with air parcel trajectories, it was estimated that, under certain conditions, over 100 ppb of ozone are transported from the Midwest to the Northeastern Atlantic Coast.

The analysis of exposure is a necessary feature of epidemiological studies. In the case of low-risk cancer agents, the examination of potential exposure should follow a sequence that prioritizes the major media and routes of concern. This will minimize the misclassification of exposure and the failure to identify important co-factors, e.g. contamination in other media, etc. The manuscript describes specific components of exposure analysis and provides examples that pertain to single and multimedia exposure problems. The approach is examined by using the Total Human Environmental Exposure Study (THEES) for benzo(a)pyrene as a potential model for low-risk cancer agents. Since benzo(a) pyrene can be found in air, water, soil and food, and has a number of sources, THEES illustrates how to prioritize an exposure assessment, take advantage of opportunities to conduct micro-environmental measurements, and collect personal monitoring and biological marker samples. A daily activity log is briefly described.