Average Exposure Levels Research Articles

Beryllium contamination and exposure monitoring in an inhalation laboratory setting

Beryllium (Be) is used in several forms: pure metal, beryllium oxide, and as an alloy with copper, aluminum, or nickel. Beryllium oxide, beryllium metal, and beryllium alloys are the main forms present in the workplace, with inhalation being the primary route of exposure. Cases of workers with sensitization or chronic beryllium disease challenge the scientific community for a better understanding of Be toxicity. Therefore, a toxicological inhalation study using a murine model was performed in our laboratory in order to identify the toxic effects related to different particle sizes and chemical forms of Be. This article attempts to provide information regarding the relative effectiveness of the environmental monitoring and exposure protection program that was enacted to protect staff (students and researchers) in this controlled animal beryllium inhalation exposure experiment. This includes specific attention to particle migration control through intensive housekeeping and systematic airborne and surface monitoring. Results show that the protective measures applied during this research have been effective. The highest airborne Be concentration in the laboratory was less than one-tenth of the Quebec OEL (occupational exposure limit) of 0.15 microg/m(3). Considering the protection factor of 10(3) of the powered air-purifying respirator used in this research, the average exposure level would be 0.03 x 10(- 4) microg/m(3), which is extremely low. Moreover, with the exception of one value, all average Be concentrations on surfaces were below the Quebec Standard guideline level of 3 microg/100 cm(2) for Be contamination. Finally, all beryllium lymphocyte proliferation tests for the staff were not higher than controls.

Secondhand smoke exposure (PM2.5) in outdoor dining areas and its correlates

BackgroundThis study assessed the magnitude of secondhand smoke (SHS) exposure when people smoke in outdoor dining areas and explored conditions influencing exposure levels.MethodsData were gathered from 69 outdoor dining areas...

Occupational exposure to silica and lung cancer risk in the Netherlands

ObjectivesThe lung cancer carcinogenicity of crystalline silica dust remains the subject of discussion. Epidemiological evidence is based on occupational cohort studies and population-based case–control studies. The aim of this study...

Fire fighting trainers’ exposure to carcinogenic agents in smoke diving simulators

It is well known that fire fighters are potentially exposed to various carcinogenic agents at a fire scene. An almost unheeded issue, however, is fire fighters’ exposure to carcinogenic agents in smoke diving simulators. Biomonitoring (urinary muconic acid, 1-naphthol and 1-pyrenol), dermal (polycyclic aromatic hydrocarbons) and occupational hygiene measurements (cyanides, hydrogen cyanide, polycyclic aromatic hydrocarbons, volatile organic compounds and formaldehyde) were used to determine how the burning material, the type of simulator and protective clothing used affect fire fighting trainers’ exposure. The highest excretion of 1-pyrenol (sampled 6 h after end of exposure, in average 4.3–9.2 nmol/L) and emissions of benzene (1.0–2.5 mg/m 3) and hydrogen cyanide (0.2–0.9 mg/m 3) were measured during the burning of conifer plywood and chipboard, and the lowest when pure pine and spruce wood (1.5 nmol/L, 0.6 mg/m 3, and 0.05 mg/m 3) was burned. However the safest burning material seemed to be propane (1.0 nmol/L, 0.2 mg/m 3, and not measured). The type of simulator used affected trainers’ exposure very clearly. The highest dermal whole body exposures to polycyclic aromatic hydrocarbons were measured in the fire house simulator (in average 1200 ng/cm 2). Clearly lower exposure levels were measured in container training sessions (760 ng/cm 2), where the average dermal exposure level was 35% lower than in the fire house. The exposure levels (30 ng/cm 2) in the gas simulator in turn, were only 4% of the levels in container training sessions. The amount of polycyclic aromatic hydrocarbons decreased by 80% on trainers’ hands when they used under gloves (in average 8.7 ng/cm 2) compared to those (48.4 ng/cm 2) who did not. There was not difference in protection efficiency against polycyclic aromatic hydrocarbons between tested fire suits (Brage and Bristol).

Job Strain and Ischemic Heart Disease: A Prospective Study Using a New Approach for Exposure Assessment

Prolonged psychosocial load at the workplace may increase the risk of ischemic heart disease (IHD), but the issue is still unsettled. We analyzed the association between psychosocial workload and risk of IHD using a new approach allocating measures of psychosocial load to individuals based on the average exposure level in minor work units. Cohort study of 18,258 Danish public service workers in 1106 work units; 79% were women; 108 subjects with history of cardiovascular disease were excluded from the follow-up. The outcome was hospitalization due to IHD (angina pectoris or myocardial infarction) during the period 2002 to end of 2007. During 87,428 person-years at risk (mean follow-up = 4.82 years), 101 subjects were admitted to a hospital due to IHD. Neither job strain (synergy of job demands and job control) nor general job dissatisfaction were related to IHD risk. However, compared with others, subjects who were allocated to the low job control category, had an increased risk of IHD, Hazard Ratio (95% CI) = 2.0 (1.1 to 3.6). The findings presented do not lend support to the hypothesis that high job strain and job dissatisfaction are important determinants for IHD among Danish predominantly female public service workers.

RIESGO PARA LA SALUD POR RADIACIONES NO IONIZANTES DE LAS REDES DE TELECOMUNICACIONES EN EL PERÚ

We review the various studies on the potential impact of telecommunications networks on health, these studies relate to the possible health effects due to thermal effect of non-ionizing radiation produced greater increases in body temperature at 1 oC. furthermore, the studies were reviewed for assessment of exposure to non-ionizing radiation of telecommunications networks in Peru from 2000 to 2006 that include the measurement of more than 500 locations. The highest average levels of exposure in Peru are produced by the fM radio and are in the order of 29% of the recommended limits, while those produced by the mobile base stations are at 1.5% population. The highest levels of exposure are given by mobile phones but still within the permissible limits. The risk assessment of non-ionizing radiation of telecommunications networks in Peru shows that the health risk of the fixed stations is not significant, but in the case of stations (cell) the risk is higher and its importance depend on the results of international investigations that are ongoing.

Assessment of noise level in sundry processing and manufacturing industries in Ilorin metropolis, Nigeria

In this work, noise level in five selected processing and manufacturing industries in Ilorin are evaluated and compared. Emphasis is given to noise emitted by individual industrial machinery from the selected industries. Event L(Aeq) and L(N) cycles were studied to identify the noisy machines and to generate baseline data. Findings show that hammer mill machine from mineral-bearing rock-crushing mills produced the highest average noise [98.4 dB(A)], an electric generator 1 [95.6 dB(A)] from the soft drink bottling industry, an electric generator [97.7 dB(A)] from the beer brewing and bottling industry, a vacuum pump [93.1 dB(A)] from the tobacco making industry, and an electric generator 2 [94.1 dB(A)] from the mattress-making industry. The highest and lowest average noise exposure levels are recorded in mineral-bearing rock-crushing mills [93.16 dB(A)] and the mattress making industry [84.69 dB(A)], respectively. The study shows that, at 95% confidence level, there is significant difference (P < 0.05) in noise levels in the industries surveyed. The percentages of machines that emit noise above Federal Environmental Protection Agency and Occupational Safety and Health Administration recommendations [90 dB(A)] are from the soft drink bottling industry (83.3%), the beer brewing and bottling industry (42.9%), the tobacco making industry (71.4%), the mattress making industry (11.1%), and minerals crushing mills (87.5%). In the past 20 years, the noise levels in the soft drink bottling industry were reduced by 0.58 dB(A), and those of the beer brewing and bottling industry were reduced by 9.66 dB(A). However, that of the mattress making industry increased by 2.69 dB(A). On average, the noise level in these industries has been reduced by 2.52 dB(A). The results of this study show that the noise control measures put in place have significant impacts on the noise exposure level in the industries surveyed.

Cancer du rein et expositions au trichloroéthylène : les valeurs limites d’exposition professionnelle françaises en vigueur sont-elles adaptées ?

Background Several studies have investigated the association between trichloroethylene (TCE) exposure and renal cell cancer (RCC) but findings were inconsistent. The analysis of a case control study has shown an increased risk of RCC among subjects exposed to high cumulative exposure. The aim of this complementary analysis is to assess the relevance of current exposure limits regarding a potential carcinogenic effect of TCE on kidney. Methods Eighty-six cases and 316 controls matched for age and gender were included in the study. Successive jobs and working circumstances were described using a detailed occupational questionnaire. An average level of exposure to TCE was attributed to each job-period in turn. The main occupational exposures described in the literature as increasing the risk of RCC were assessed as well as non-occupational factors. A conditional logistic regression was performed to test the association between TCE and RCC risk. Three exposure levels were studied (average exposure during the eight-hour shift): 35 ppm, 50 ppm and 75 ppm. Potential confounding factors identified were taken into account at the threshold limit of 10% ( p = 0.10) (body mass index [BMI], tobacco smoking, occupational exposures to cutting fluids and to other oils). Results Adjusted for tobacco smoking and BMI, the odd-ratios associated with exposure to TCE were respectively 1.62 [0.77–3.42], 2.80 [1.12–7.03] and 2.92 [0.85–10.09] at the thresholds of 35 ppm, 50 ppm and 75 ppm. Among subjects exposed to cutting fluids and TCE over 50 ppm, the OR adjusted for BMI, tobacco smoking and exposure to other oils was 2.70 [1.02–7.17]. Conclusion Results from the present study as well as those provided in the international literature suggest that current French occupational exposure limits for TCE are too high regarding a possible risk of RCC.

An Overview of Industrial Employees' Exposure to Noise in Sundry Processing and Manufacturing Industries in Ilorin Metropolis, Nigeria

In this work, an overview of industrial employees' noise exposure level in five selected processing and manufacturing industries in Ilorin are evaluated and compared. Emphasis is given to noise emitted by individual industrial machinery from the selected industries. Event L(Aeq) and LN cycle were studied to identify the noisy machines and to generate baseline data. Findings show that, hammer mill machine from mineral crushing mills produced the highest average noise (98.4 dB(A), electric generator1 (95.6 dB(A) from soft drink bottling industry, electric generator (97.7 dB(A)) from beer brewing and bottling industry, vacuum pump (93.1 dB(A)) from tobacco making industry and electric generator 2 (94.1 dB(A) from mattress making industry. The highest and lowest average noise exposure levels are recorded in mineral crushing mills (93.16 dB(A)) and mattress making industry (84.69 dB(A)) respectively. The study shows that at 95% confidence level, there is significant difference (p<0.05) in noise levels in the industries surveyed. The percentages of machines emit noise above FEPA and OSHA recommendation (90 dB(A)) are: soft drink bottling industry (83.3%), beer brewing and bottling industry (42.9%), tobacco making industry (71.4%), mattress making industry (11.1%) and minerals crushing mills (87.5%). In the past 20 years, the noise levels in soft drink bottling industry reduced by 0.58 dB(A) and that of beer brewing and bottling industry reduced by 9.66 dB(A). But that of mattress making industry increased by 2.69 dB(A). On the average, the noise level in these industries has reduced by 2.52 dB(A). The results of this study show that the noise control measures put in place have significant impact on the noise exposure level in the industries surveyed.

Source apportionment of VOCs at the petrol pumps in Kolkata, India; exposure of workers and assessment of associated health risk

Ambient air quality at five busy petrol pumps in Kolkata, India is monitored for mono-aromatic hydrocarbons and carbonyls. Among the measured volatile organic compounds, toluene and formaldehyde were the most abundant. Source apportionment using chemical mass balance identified exhaust from roadway and refueling as the major sources. Monitoring of the service station workers revealed that the average exposure level for benzene and toluene were 3.9 and 5.5 fold higher than the ambient air. The integrated lifetime cancer risks due to benzene, ethylbenzene, formaldehyde and acetaldehyde and the overall hazard index due to chronic exposure to some hazardous volatile organic compounds are 1.48E−04 and 2.3 indicating the probability of cancer as well as chronic health effect on the workers exposed.

Wheat allergen exposure and the prevalence of work‐related sensitization and allergy in bakery workers

Occupational airway diseases are common among bakers. The present study describes the association between exposure to wheat allergen levels and sensitization to wheat allergens, work-related upper and lower respiratory symptoms and asthma in bakery workers. As part of a Health Surveillance System for early detection of (allergic) occupational airway diseases a so-called 'validation study' was performed among Dutch bakers for validation of a diagnostic model that predict the likelihood of sensitization to specific workplace allergens. The present study used serology and questionnaire results of a subgroup of 860 bakers participating in the validation study. An earlier developed job-exposure matrix was used to predict average and cumulative personal exposure to wheat allergens. The prevalence of wheat sensitization, work-related respiratory symptoms and asthma increased till average wheat exposure levels of approximately 25-30 microg/m3, leveled off and decreased at higher exposure concentrations. Exposure-response curves showed a stronger pronounced bell-shape with cumulative exposure. Associations were strongest for asthma and work-related lower respiratory symptoms (PR approximately 2 and PR approximately 3.5-4.5 for average and cumulative exposure, respectively). Associations were only found in atopics. Wheat sensitization was an important factor in the prevalence of respiratory symptoms. In accordance with earlier studies, the present study showed a bell-shaped exposure-response relationship especially for cumulative wheat allergen exposure with sensitization, allergic respiratory symptoms and asthma. The healthy worker effect may be the possible explanation for the bell-shaped relationship.

Exposure to Environmental Tobacco Smoke at Work, at Home, and During Leisure Time: Personal Exposure Measurements by Diffusive Sampling of Airborne 3-Ethenylpyridine

Environmental tobacco smoke (ETS) is associated with an increased risk of several diseases. In 2002, the ETS exposure level was studied in a Finnish cross-sectional population sample with a sub-sample of currently working nonsmokers. In all, 123 nonsmokers (25—64 years) reporting at least 1 h of daily exposure to ETS participated in personal exposure measurements. Two 3 M organic vapor monitors, one for work and one for free time, were given to each participant. A 5-day sampling of breathing zone air was based on the passive monitoring of 3-ethenylpyridine (3-EP), a vapor-phase compound specific to tobacco smoke. The 3-EP concentrations ranged from &lt;0.01 to 30 μg·m-3 (n=221), with low exposures as the most frequent. More than half (55%) of the study group was exposed both at work and during free time. The geometric mean concentration for 3-EP at home and during leisure time was 0.07 μg·m-3 (mean sampling time 74 h) and during working hours 0.30 μg·m-3 (mean sampling time 32 h). The study showed that despite the restrictions concerning indoor smoking at work, the ETS exposure seemed to be higher at work than at home or during leisure time. The average exposure levels were similar for men and women.

RECENT TRENDS IN EXPOSURE TO SECONDHAND SMOKE IN THE UNITED STATES (US) POPULATION

PURPOSE: Exposure to secondhand smoke (SHS) is an important and preventable cause of morbidity and mortality in the US. Pirkle et al. have published two articles on the average secondhand smoke exposure level in nonsmokers using data from the National Health and Nutrition Surveys (NHANES). The most recent study estimated a significant downward trend in exposure between 1988 to 2002. The objective of this study was to assess whether the downward trend has continued in the latest NHANES data available through 2006.

Evaluation of Peak Exposures in the Dutch Flour Processing Industry: Implications for Intervention Strategies

To effectively decrease occupational exposure to flour dust and related allergens, detailed information on exposure determinants and effectiveness of control measures is essential. In this paper, we use personal real-time exposure measurements to get more insight into the relationship between specific work characteristics, including the use of control measures, and (peak) exposure to flour dust. The study has three objectives: (i) identify tasks and activities related to peak exposure, (ii) identify control measures and other important exposure determinants and (iii) assess the potential impact of these control measures on the (peak) exposure to flour dust. A data set containing 82 real-time exposure measurements in combination with information from detailed observations was used to study the association between peak exposures and different tasks, activities and other determinants such as control measures. Descriptive statistics of peak exposure on job level were generated as well as information on contribution of task-specific peak exposures to time-weighted average (TWA) exposure levels. Finally, we evaluated the efficacy of a variety of control measures on task exposure by comparing exposure levels of groups of workers with and without controls. In workers included in this study, >75% of TWA exposure is directly associated with peak exposures during a limited set of well-defined tasks/activities. The impact of a single task on population TWA exposure is generally limited (<40%). Worker behavior seems an important determinant in effective exposure control for many tasks. Data from real-time measurements provide important detailed information with respect to exposure determinants and control measures, not obtainable from conventional measurement studies focusing at TWA exposure. This information is essential to perform prospective impact assessments of intervention strategies on the populations' exposure distribution.

DNA adducts and PM 10 exposure in traffic-exposed workers and urban residents from the EPIC-Florence City study

Air pollution and particulate matter in urban areas have been associated with increased mortality from cardiovascular and respiratory diseases and increased cancer risk. Carcinogenic effects of particulate matter have been related to the contents of specific compounds, such as polycyclic aromatic hydrocarbons. The latter may form bulky DNA adducts, that may be considered as candidate markers of cancer risk. We have recently shown that traffic-exposed workers and the general population in Florence have divergent levels of DNA adducts, possibly related to different levels of exposure to genotoxic agents from vehicle emissions. In the current study, in a series of 214 Florence City healthy adults enrolled in a prospective study in the period 1993–1998 (152 residents / 62 traffic-exposed workers), we investigated the correlation between individual levels of DNA bulky adducts and PM 10 exposure scores based on daily environmental measures provided by the local Environmental Protection Agency for the whole study period, by two types of urban monitoring stations (high- and low-traffic). We found that PM 10 cumulative scores from high-traffic stations over the last 1–2 weeks prior to blood drawing significantly correlated ( r = 0.58, p = 0.02) with DNA adduct levels among non-smoking traffic-exposed workers (but not among residents with no occupational exposure to vehicle emissions). A multivariate regression analysis adjusted for possible confounders confirmed these findings. PM 10 scores from low-traffic stations did not show any correlation. These results show that DNA adduct levels in non-smoking workers reflect the average levels of exposure to PM 10 in high-traffic urban areas experienced over a time period of 1–2 weeks. Since DNA adduct levels have been found predictive of lung cancer risk, our findings provide clues relevant to the reduction of genotoxic damage and possibly cancer risk among traffic-exposed urban workers.

Perfluorinated compounds – Exposure assessment for the general population in western countries

Perfluorinated compounds (PFCs) can currently be detected in many environmental media and biota, as well as in humans. Because of their persistence and their potential to accumulate they are of toxicological concern. The present review presents the current knowledge of PFC monitoring data in environmental media relevant for human exposure. In this context, PFC concentrations in indoor and ambient air, house dust, drinking water and food are outlined. Furthermore, we summarize human biomonitoring data of PFC levels in blood, breast milk, and human tissues. An estimate of the overall exposure of the general adult population is provided and compared with tolerable intake values. Using a simplified model, the average (and upper) level of daily exposure including all potential routes amounts to 1.6 ng/kg(body weight) (8.8 ng/kg(body weight)) for PFOS and 2.9 ng/kg(body weight) (12.6 ng/kg(body weight)) for PFOA in adults in the general population. The majority of exposure can be attributed to the oral route, mainly to diet. Overall, the contribution of PFOS and PFOA precursors to total exposure seems to be limited. Besides this background exposure of the general population, a specific additional exposure may occur which causes an increased PFC body burden. This has been observed in populations living near PFC production facilities or in areas with environmental contamination of PFCs. The consumption of highly contaminated fish products may also cause an increase in PFC body burdens.

Media Exposure and Sensitivity to Violence in News Reports: Evidence of Desensitization?

This study explores whether amount of exposure to entertainment television violence, local newspapers, and local television news relates to reactions to reading news stories that recount violent events. Survey results from three regions in the United States show bivariate connections between average media exposure levels and each of three indicators of desensitization. Multivariate results provide partial support for the idea that heavy local news consumption—presumably due to the presence of violent content—can contribute to a blunted response to news stories regarding real-life violent events when individuals have low trait empathy.

Assessing inhalatory and dermal exposures and their resultant health-risks for workers exposed to polycyclic aromatic hydrocarbons (PAHs) contained in oil mists in a fastener manufacturing industry

This study first assessed workers' inhalatory and dermal exposures to polycyclic aromatic hydrocarbons (PAHs) contained in oil mists. Then, their resultant lung cancer and skin cancer risks were estimated. Finally, control strategies were initiated from the health-risk management aspect. All threading workers in a fastener manufacturing plant were included. 16 inhalatory and 88 dermal PAH exposure samples were collected. Results show that the inhalatory gas phase total PAH exposure level (8.60 × 10 4 ng/m 3) was much higher than that of particle phase (2.30 × 10 3 ng/m 3). Workers' mean inhalatory exposure level (8.83 × 10 4 ng/m 3) was lower, but its corresponding 1-sided upper 95% confidence level (UCL 1,95% =1.02 × 10 5 ng/m 3) was higher than the time-weighted average permissible exposure level (PEL-TWA) regulated in Taiwan for PAHs (1.00 × 10 5 ng/m 3). The mean whole body total PAHs dermal exposure levels was 5.44 × 10 6 ng/day and the top five exposed surface areas were lower arm, hand, upper arm, neck, and head/front. The estimated lifetime skin cancer risk (9.72 × 10 − 3 ) was lower than that of lung cancer risk (1.64 × 10 − 2 ), but both were higher than the significant risk level (10 − 3 ) defined by the US Supreme Court in 1980. The installation of a local exhaust ventilation system at the threading machine should be considered as the first priority measurement because both lung and skin cancer risks can be reduced simultaneously. If the personal protection equipment would be adopted in the future, both respiratory protection equipment and protective clothing should be used simultaneously.

Reduction of Respirable Silica Following the Introduction of Water Spray Applications in Indian Stone Crusher Mills

Respirable crystalline silica dust generated during stone crushing operations has been linked to chronic lung disease and increased risk of tuberculosis. In India, most stone crushing mills operate without any dust control or containment systems. This investigation in the Khurda District of Orissa demonstrated a reduction in respirable particulate mass following the application of a fine mist of water. Average respirable quartz and cristobalite levels declined 82% and 69%, respectively, after water spray controls were installed. This finding suggests that relatively inexpensive modifications that are available in the local market can be effective at reducing silica exposures. Although average exposure levels, particularly during the dry season, may exceed the Permissible Exposure Limit for silica, the overall reductions observed were substantial. Widespread adoption of this simple control technology by stone crushers in India could have a positive public health impact.

Exposure to inhalable dust and its cyclohexane soluble fraction since the 1970s in the rubber manufacturing industry in the European Union

Objectives: As exposures to airborne particulates in the European rubber industry might still be causing genotoxic risks, it is important to assess trends in levels of inhalable dust and its...