Evaluation of worker exposure to polycyclic aromatic hydrocarbons

A sampling and analytical method was selected to determine the physical and chemical nature of worker exposure to polycyclic aromatic hydrocarbons (PAH). It consists of filter and sorbent tube sampling followed by benzene extraction and analysis of 12 different PAHs with a gas chromatograph connected to a mass spectrometer. This method has undergone extensive field trials. Sampling temperature, inorganic and organic interferences have an effect on the results as they do on the standard gravimetric method of benzene-solubles. A combination of the gravimetric method and the particulate and gaseous concentration profile of 12 PAHs is necessary to obtain an informative evaluation of worker exposure. This approach was used to demonstrate that workers in paving and roofing operations and on some worksites in the steel and silicon carbide industries show an exposure profile that suggests minimal health risk and is largely different from the exposure of workers in aluminum refineries, refractory brick laying and most other worksites in the silicon carbide industry.     

Evaluation of occupational exposure to aromatic polycyclic hydrocarbons in bituminous pulp plants]

A method was developed for isolation of aromatic polycyclic hydrocarbons (APH) from atmospheric air. Air samples were filtered through Whatman GF/C filter papers, subsequently extracted with benzene. Aromatic polycyclic hydrocarbons were isolated from the extract, purified by column chromatography on aluminium oxide and determined by gas chromatography. This method was applied to determine qualitatively and quantitatively: naphthalene, anthracene, pyrene, perilene, biphenyl, fluoranthene, phenanthrene, benzo(a)pyrene, dibenzo(a,c)anthracene, dibenzo(g,h)anthracene, 11H-benzo(a)fluorane, 11H-benzo(b)fliorene, benzo(g,h,i)perylene, benzo(a)anthracene, chrysene, indene and durene. Professional exposure in years 1977-1989 was comparatively assessed using the evaluation criterion for APH expressed as the benzene fraction (0.2 mg/m3--USA standard) and as benzo(a)pyrene (0.00015 mg/m3--USSR standard). According to the accepted standards, working conditions in the examined plants entail a risk for the employees. Comparison of the results obtained before and after reconditioning of the machinery suggests the need for further modernization aimed at application of new technical solutions allowing for limitation of pollutant emission to air.     

General population exposure to volatile aromatic hydrocarbons

Aromatic hydrocarbons benzene, toluene, ethylbenzene, and isomeric xylenes (BTEX) are volatile organic compounds widespread in the biosphere because of their physical and chemical properties and their use. They are major constituents of gasoline, and vehicular traffic is the main source of BTEX in the environment. Significant additional exposure to BTEX results from tobacco smoking. General population is more or less permanently exposed to BTEX. This review summarises their distribution in the environment, analytical methods for BTEX determination in biological samples, and published data on BTEX concentrations in blood, exhaled air and urine samples of general population. The paper also describes toxic effects of BTEX on human health associated exclusively with professional exposure. Concentrations of these compounds in biological samples collected from general population reflect environmental pollution. Biological monitoring of people exposed to environmental BTEX concentrations is the first step toward evaluating health risk.     

Membranous nephropathy following exposure to volatile hydrocarbons

Membranous nephropathy occurred in four male patients following exposure of 2, 11, 18, and 20 years, respectively, to various organic solvents. There was absorption through lungs and skin. It is impossible to identify the causative agent among the substantial number of solvents to which the individuals were exposed. There may be a causal relationship between membranous nephropathy and solvent exposure. Although the mechanism of production of membranous nephropathy in these cases is not known, an indirect immunological process mediated by endogenous tubular antigen is suggested. Exposed individuals may have proteinuria for long periods before onset of overt manifestations. Examination for proteinuria is a simple method of screening in these cases.     

Evaluation of occupational exposure to mixed dusts and polycyclic aromatic hydrocarbons in silicon carbide plants

Workers in the silicon carbide industry have experienced occupational health diseases, particularly lung disorders such as silicosis. The silicon carbide production process mainly employs petroleum coke, sawdust, pure crystalline silica and graphite. Since crystalline silica is present in the occupational environment, the airborne dust content of various polymorphs of silica, especially quartz, cristobalite and tridymite, was determined by X-ray diffraction analysis. The analytical method was modified to eliminate graphite, since it overlaps with the main diffraction plane of quartz. Exploratory field surveys were conducted to identify the minerals present in that occupational environment and to evaluate the validity of the analytical method. The surveys provided information on the mineralogical nature of the dust, its respirable content and the concentration of silica polymorphs. Polycyclic aromatic hydrocarbons also were measured, and the effect of their adsorption on graphite was evaluated.     

Cardiac arrhythmias during occupational exposure to fluorinated hydrocarbons

The effects of occupational exposure to chlorodifluoromethane (FC 22) and dichlorodifluoromethane (FC 12) on cardiac rhythm were examined. The subjects were six men who repaired refrigerators (age 31-56, mean 46 years) and a control group of six plumbers (age 29-54, mean 45 years). Ambulatory electrocardiograms (ECG) were recorded for 24 hours on the day of exposure and on a control day. The ECG tapes were automatically analysed with a Reynolds pathfinder 3 apparatus and all aberrant complexes recorded by the machine were checked. One person read all the tapes without knowing whether or not they were recorded during exposure. The number of ventricular ectopic beats were compared between the day of exposure and the control day and with the tape of the control. In addition, the number of ventricular ectopic beats during exposure was compared with the number occurring during the rest of the day. The concentrations of fluorocarbons were measured in four instances. High peak concentrations of fluorocarbons (1300-10,000 cm3/m3) were measured during refrigerator repair work. No clear connection between fluorocarbons and cardiac arrhythmia was found, although one subject had several ventricular ectopic beats which may have been connected with exposure.     

Environmental exposure of small children to polycyclic aromatic hydrocarbons

Objectives: The aim of the study was to assess the intake (by various routes of exposure) of polycyclic aromatic hydrocarbons (PAH) by children living in a Czech city, and its effect on excretion of 1-hydroxypyrene (1-OHP) in summer and winter periods. Methods: Four groups of children (3–6 years old) were chosen: (1) two groups from a kindergarten situated in the city center with a higher traffic density (“polluted” area); (2) two groups from a kindergarten situated in a green zone of the same city (“non-polluted” area). Food consumption was recorded in all children and PAH intake from foodstuffs was estimated. Ambient air samples were collected from the playground and inside the kindergartens. Soil samples were collected too. Morning and evening urine samples were collected during sampling days. Results: In both seasons, the mean outdoor total PAH concentration (sum of 12 individual PAH) in the “polluted” area was approximately three-times higher than that in the “non-polluted” area. Indoor concentration in the “polluted” area was more than six-times higher than that in the “non-polluted” area in summer, and almost three-times higher in winter. The same trend was observed for pyrene and for the sum of carcinogenic PAH. The contribution to the total pyrene absorbed dose from food consumption was much more important than that from inhalation and from ingestion of soil dust. Significantly higher urinary concentrations of 1-OHP (evening samples) were found in children from the “polluted” kindergarten in both seasons. The number of significant relationships between 1-OHP and pyrene absorbed dose was weak. Conclusions: Food seems to be the main source of total pyrene and total PAH intake in small children, even under relatively higher air PAH exposure in the city. Estimated pyrene ingestion from soil had a negligible contribution to the total pyrene absorbed dose. Urinary 1-OHP seems to be an uncertain (non-sensitive) marker of the environmental inhalation exposure to pyrene (PAH) if the pollution of air by pyrene (PAH) is not excessive and the pyrene (PAH) dose by this route is much less than by ingestion. Usefulness of the urinary 1-OHP as an indicator of overall environmental exposure to PAH needs further investigation. Received: 18 September 2000 / Accepted: 20 February 2001     

Health risks of residential exposure to polycyclic aromatic hydrocarbons

A disease prevalence study and follow-up health surveillance were conducted among residents of an African-American community situated at the site of a former creosote wood-treatment facility contaminated with polycyclic aromatic hydrocarbons. Household interviews were conducted among 214 residents living around the hazardous waste site (target population) and 212 comparison residents in a neighborhood 2.4 km away from the site. Target area residents reported a higher prevalence of skin rashes than comparison residents (relative risk [RR] = 5.7; 95% confidence interval [CI] = 3.0, 10.9). The prevalence of reported rashes increased with increasing levels of anthracene detected in yards (test for linear trend, p = 0.02). With adjustment for environmental worry, reports of chronic bronchitis and difficulties becoming pregnant did not differ significantly between target and comparison residents (p > 0.05).     

Estimation of personal exposure to tobacco smoke with a newly developed nicotine personal monitor

To evaluate the actual level of exposure of nonsmokers to tobacco smoke in their living environments, a convenient personal monitor of nicotine specific for tobacco smoke has been developed. The nicotine personal monitor consists of a sampler tube containing 450 mg of Uniport-S coated with silicon OV-17 and a portable sampling pump with a mechanical counter for obtaining total sampling volume. Using the personal monitor attached to a nonsmoker, ambient nicotine was collected in the sampler tube by drawing environmental air at a constant flow rate for a maximum period of 8 hr. The collected nicotine was desorbed by heating and directly transferred onto a GC column with a carrier gas. The amounts of nicotine inhaled by passive smoking in various living environments were estimated to be in the range of 0.9-40 micrograms/hr. These levels are equivalent to those from the active smoking of about 0.001-0.044 ordinary cigarettes in 1 hr.     

Cancer risk due to occupational exposure to polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) demonstrate carcinogenic activity in animal models. Although some epidemiologic studies have implicated PAHs as risk factors for human cancer, the evidence reported to date has not been consistent. The purpose of this report is to describe the associations between occupational exposure to PAHs in the workplace and each of 14 types of cancer. A population-based, case-control study was carried out in Montreal to investigate associations between a large variety of environmental and occupational exposures on the one hand, and several types of cancer on the other. A detailed job history was obtained from each subject along with information on a number of potential confounders. Each job history was reviewed by a team of experts, who used this information to construct a corresponding history of occupational exposures. Among the PAH exposures considered were benzo(a)pyrene (B(a)P) and five categories of PAHs defined on the basis of the source material, namely, wood, petroleum, coal, other sources, and any source. Altogether, 3,730 cancer patients and 533 population controls were interviewed and their job exposure histories coded. For each of 14 types of cancer analyzed, three control groups were available: other cancer patients, population controls, and the pooled set of cancer and population controls. The associations between 14 cancer types and 6 PAH exposures were analyzed using logistic regression methods. For most types of cancer evaluated, there was no evidence of excess risk due to PAHs at the levels encountered in the occupations in which PAH exposure has been prevalent in the Montreal area. For a few cancer sites–the esophagus, the pancreas, and the prostate gland–there were suggestions of excess risk; these observations are noteworthy hypotheses for further investigation. For lung cancer, there appeared to be an increased risk due to PAHs among nonsmokers and light smokers, but not among heavy smokers.     

Ambient concentrations and personal exposure to polycyclic aromatic hydrocarbons (PAH) in an urban community with mixed sources of air pollution

Assessment of the health risks resulting from exposure to ambient polycyclic aromatic hydrocarbons (PAH) is limited by a lack of environmental exposure data among the general population. This study characterized personal exposure and ambient concentrations of PAH in the Village of Waterfront South (WFS), an urban community with many mixed sources of air toxics in Camden, New Jersey, and CopeWood/Davis Streets (CDS), an urban reference area located ～1 mile east of WFS. A total of 54 and 53 participants were recruited from non-smoking households in WFS and CDS, respectively. In all, 24-h personal and ambient air samples were collected simultaneously in both areas on weekdays and weekends during summer and winter. The ambient PAH concentrations in WFS were either significantly higher than or comparable to those in CDS, indicating the significant impact of local sources on PAH pollution in WFS. Analysis of diagnostic ratios and correlation suggested that diesel truck traffic, municipal waste combustion and industrial combustion were the major sources in WFS. In such an area, ambient air pollution contributed significantly to personal PAH exposure, explaining 44-96% of variability in personal concentrations. This study provides valuable data for examining the impact of local ambient PAH pollution on personal exposure and therefore potential health risks associated with environmental PAH pollution.     

Cardiac arrhythmias during occupational exposure to fluorinated hydrocarbons.

The effects of occupational exposure to chlorodifluoromethane (FC 22) and dichlorodifluoromethane (FC 12) on cardiac rhythm were examined. The subjects were six men who repaired refrigerators (age 31-56, mean 46 years) and a control group of six plumbers (age 29-54, mean 45 years). Ambulatory electrocardiograms (ECG) were recorded for 24 hours on the day of exposure and on a control day. The ECG tapes were automatically analysed with a Reynolds pathfinder 3 apparatus and all aberrant complexes recorded by the machine were checked. One person read all the tapes without knowing whether or not they were recorded during exposure. The number of ventricular ectopic beats were compared between the day of exposure and the control day and with the tape of the control. In addition, the number of ventricular ectopic beats during exposure was compared with the number occurring during the rest of the day. The concentrations of fluorocarbons were measured in four instances. High peak concentrations of fluorocarbons (1300-10,000 cm3/m3) were measured during refrigerator repair work. No clear connection between fluorocarbons and cardiac arrhythmia was found, although one subject had several ventricular ectopic beats which may have been connected with exposure.     

Estimation of personal exposure to ambient nicotine in daily environment

Summary To evaluate the actual exposure level of nonsmokers to environmental tobacco smoke (ETS) in their daily life, the exposure level of ambient nicotine was measured with a nicotine personal monitor carried by a nonsmoker. Average exposure levels of nicotine, even in such smoky places as cars, coffee shops and pubs, were less than 45 g/m³. As a result of all-day monitoring, the highest amount of nicotine inhaled in a day was estimated, in this study, to be up to 310 g, equivalent to actively smoking 0.31 ordinary cigarettes.     

Evaluation of a personal monitor employing an electrochemical sensor for assessing exposure to hydrogen peroxide in the workplace

A commercially available direct-reading instrument designed for personal monitoring of vapor phase hydrogen peroxide (VHP) was evaluated in the laboratory and the workplace. Monitoring VHP has gained increasing importance in the pharmaceutical industry because sterilization using VHP has proven to be a good alternative to previously used sterilizing methods. The current Occupational Safety and Health Administration impinger method for VHP measurements, based on bubbling air through an acid solution with subsequent laboratory analysis, is not practical for monitoring personal exposures. By employing an electrochemical sensor, the instrument evaluated provides real-time exposure data with auxiliary functions such as displaying concentrations in parts per million, data logging, and alarms. A double-dilution technique using a syringe pump was used to generate dynamic test atmospheres ranging from 0.2 to 10 ppm in an exposure chamber. Time-weighted average concentration data from the direct-reading instrument was compared with concentration data from the impingers. The overall accuracy was less than the +/-25%, National Institute for Occupational Safety and Health criterion. No significant differences in accuracy were observed at three humidity levels (i.e., 15, 50, and 80%). The instrument was similarly evaluated in a workplace under typical conditions. The results agreed within +/-0.2 ppm. Selected performance characteristics of the instrument also were investigated, including reproducibility, response and recovery times, calibration frequency, and suitability of the calibration adapter. Results of the investigation suggest that the instrument provides a means for simple and accurate monitoring of personal exposures to VHP in workplace environments.     

Human exposure to volatile halogenated hydrocarbons from the general environment

Summary The objective of this study was to assess individual human exposure to volatile halogenated hydrocarbons (VHH) under normal environmental conditions by means of biological monitoring, i.e. by the measurement of these compounds or their metabolites in body fluids, such as blood, serum, and urine. Blood samples of 39 normal subjects without known occupational exposure to these agents were examined for the occurrence of VHH. The following compounds were present in quantifiable concentrations in 60 to 95% of the blood samples examined: chloroform (median 0.2 g/l; range < 0.1–1.7 g/l), 1,1,1-trichloroethane (median 0.2 g/l; range < 0.1–3.4 g/l), tetrachloroethylene (median 0.4 g/l; range < 0.1–3.7 g/l). Trichloroethylene could be detected in 31% of all blood samples (median < 0.1 g/l; range < 0.1–1.3 g/l). In addition, the levels of trichloroacetic acid (TCA) were determined in serum and 24-h urine samples of 43 and 94, respectively, normal subjects. TCA was present in measurable concentrations in all serum and urine samples examined. The median of the TCA levels in serum was 21.4 g/l (range 4.8–221.2 g/l) and in urine 6.0 g/24 h (range 0.6–261.4 g/24 h). The results are discussed in relation to data from the literature on human exposure to VHH from the general environment, i.e. via air, food, and water. The upper normal limits calculated from the results of this investigation can be used to detect even minor excessive exposures to VHH.