Occupational exposure levels to benzene in Italy: findings from a national database

Occupational Co-exposures to Multiple Chemical Agents from Workplace Measurements by the US Occupational Safety and Health Administration

OBJECTIVES

The occupational environment represents an important source of exposures to multiplehazards for workers' health. Although it is recognized that mixtures of agents may have differenteffects on health compared to their individual effects, studies generally focus on the assessment ofindividual exposures. Our objective was to identify occupational co-exposures occurring in the United States using the multi-industry occupational exposure databank of the Occupational Safety and Health Administration (OSHA).

METHODS

Using OSHA's Integrated Management Information System (IMIS), measurement data from workplace inspections occurring from 1979 to 2015 were examined. We defined a workplace situation (WS) by grouping measurements that occurred within a company, within the same occupation (i.e. job title) within 1 year. All agents present in each WS were listed and the resulting databank was analyzed with the Spectrosome approach, a methodology inspired by network science, to determine global patterns of co-exposures. The presence of an agent in a WS was defined either as detected, or measured above 20% of a relevant occupational exposure limit (OEL).

RESULTS

Among the 334 648 detected exposure measurements of 105 distinct agents collected from 14 513 US companies, we identified 125 551 WSs, with 31% involving co-exposure. Fifty-eight agents were detected with others in >50% of WSs, 29 with a proportion >80%. Two clusters were highlighted, one for solvents and one for metals. Toluene, xylene, acetone, hexone, 2-butanone, and N-butyl acetate formed the basis of the solvent cluster. The main agents of the metal cluster were zinc, iron, lead, copper, manganese, nickel, cadmium, and chromium. 68 556 WS were included in the analyses based on levels of exposure above 20% of their OEL, with 12.4% of co-exposure. In this analysis, while the metal cluster remained, only the combinations of toluene with xylene or 2-butanone were frequently observed among solvents. An online web application allows the examination of industry specific patterns.

CONCLUSIONS

We identified frequent co-exposure situations in the IMIS databank. Using the spectrome approach, we revealed global combination patterns and the agents most often implicated. Future work should endeavor to explore the toxicological effects of prevalent combinations of exposures on workers' health to prioritize research and prevention efforts.

Evaluating Antineoplastic Agents and Occupational Exposures Among Italian Workers Using SIREP Surveillance System

OBJECTIVE

The aim of the study is to evaluate exposures to antineoplastic agents at workplaces in healthcare and manufacturing in Italy.

METHODS

Data on antineoplastic agents were collected from occupational exposure registries. Statistical analysis was carried out for exposure-related variables. The number of workers potentially exposed was estimated for selected industrial sectors. Concurrent exposures were investigated using cluster analysis.

RESULTS

Overall 15,763 exposure situations were analyzed during 1996 to 2016. Most exposures occurred in healthcare (66%). A total of 11,830 workers potentially exposed to antineoplastic agents was estimated. Concurrent exposures were frequently detected in the pharmaceutical industry and among healthcare workers.

CONCLUSIONS

Occupational exposure to antineoplastic agents currently represents a matter of concern both in the chemical industry and in the healthcare sector. The growing number of agents in use supports the need to constantly control exposures.

Nickel compounds in the workplaces: Occupations and activities involving high-risk exposures in Italy

BACKGROUND

Nickel (Ni) compounds have been classified as carcinogenic to humans. The aim of the study is to evaluate exposures to Ni at workplaces in Italy.

METHODS

Data on Ni compounds were collected from an occupational exposure registry. Statistical analysis was carried out for exposure-related variables. The number of workers potentially exposed was estimated for selected industrial sectors. Concurrent exposures with other occupational carcinogens were investigated using two-step cluster analysis.

RESULTS

Overall 10 083 measurements were analyzed during 1996-2016, having a geometric mean of 2.93 μg/m³ . Most exposures occurred in manufacture of metal products (50%) and among metal finishing machine operators (46%). A total of 56 046 workers potentially exposed to Ni was estimated. Concurrent exposures were frequently detected, mainly with chromium VI and cobalt compounds.

CONCLUSIONS

Systematic recording of occupational exposures provides a data source that allows recognition of high risk situations for workers' health and helps improve exposure assessment in epidemiologic studies.

Airborne exposures associated with the typical use of an aerosol brake cleaner during vehicle repair work

Many petroleum-based products are used for degreasing and cleaning purposes during vehicle maintenance and repairs. Although prior studies have evaluated chemical exposures associated with this type of work, most of these have focused on gasoline and exhaust emissions, with few samples collected solely during the use of an aerosol cleaning product. In this case study, we assess the type of airborne exposures that would be expected from the typical use of an aerosol brake cleaner during vehicle repair work. Eight exposure scenarios were evaluated over a 2-day study in which the benzene content of the brake cleaner and potential for dilution ventilation and air flow varied. Both short-term (15 min) and task-based (≥1 hr) charcoal tube samples were collected in the breathing zone and adjacent work area and analyzed for total hydrocarbons (THCs), toluene, and benzene. The majority of personal (N = 48) and area (N = 47) samples had detectable levels of THC and toluene, but no detections of benzene were found. For the personal short-term samples, average airborne concentrations ranged from 3.1-61.5 ppm (13.8-217.5 mg/m³) for THC and 2.2-44.0 ppm (8.2-162.5 mg/m³) for toluene, depending on the scenario. Compared to the personal short-term samples, average concentrations were generally 2-3 times lower for the personal task-based samples and 2-5 times lower for the area short-term samples. The highest exposures occurred when the garage bay doors were closed, floor fan was turned off, or greatest amount of brake cleaner was used. These findings add to the limited dataset on this topic and can be used to bound or approximate worker or consumer exposures from use of aerosol cleaning products with similar compositions and use patterns.

Gender differences in occupational exposure to carcinogens among Italian workers

BACKGROUND

Many carcinogenic chemicals are still used or produced in several economic sectors. The aim of this study is to investigate differences in occupational exposure patterns to carcinogens by gender in Italy.

METHODS

Information about the most common carcinogens recorded in the Italian occupational exposures database (SIREP) for the period 1996-2015 was retrieved. Descriptive statistics were calculated for exposure-related variables (carcinogenic agent, occupational group, economic activity sector, and workforce size). The chi-square(χ²) test was used to verify differences between genders, and logistic regression analysis was performed to evaluate the association between gender and risk of having higher exposure levels, after adjusting for age. Concurrent exposures to multiple carcinogens were investigated using the two-step cluster analysis.

RESULTS

A total of 166,617 exposure measurements were selected for 40 different carcinogens. Exposed workers were only in a small proportion women (9%), and mostly aged 20-44 years (70%) in both genders. Women were more likely to be exposed than men to higher levels for several carcinogens even after correction for age at exposure, and the exposure level was significantly (p < 0.01) associated with occupation, economic sector and workforce size. The five main clusters of co-exposures identified in the entire dataset showed a differential distribution across economic sectors between genders.

CONCLUSIONS

The exposures to occupational carcinogens have distinguishing characteristics in women, that are explained in part by work and job segregation. Because of the presence of high-exposed groups of female workers in many industrial sectors, further research and prevention efforts are recommended.

[Occupational exposure to benzene in Brazil: estimates based on an occupational exposure matrix]

This study estimates the number of exposed workers and the prevalence of occupational benzene exposure in Brazil. Due to the lack of available local measurements for the study, data were used from an occupational exposure matrix, the Finnish National Job-Exposure Matrix (FINJEM), which covers proportions of individuals exposed to benzene, calculated as environmental measures. In Brazil, the 2010 Demographic Census identified 86,353,839 workers in the workforce and employed. Applying the FINJEM parameters, an estimated 7,376,761 (8.5%) belonged to potentially exposed occupational groups, while 770,212 were considered exposed to benzene, corresponding to an occupational group-weighted prevalence of 0.9%, higher in men (1.1%) than in women (0.6%). Exposed individuals were concentrated in the category of Machine and Motor Operators and Mechanics (62%). The number of exposed and prevalence of occupational exposure to benzene are high, even when compared to Finnish parameters, suggesting the need for monitoring and control of this carcinogen in Brazil.

Benzene Exposures and Risk Potential for Vehicle Mechanics from Gasoline and Petroleum-Derived Products

Benzene exposures among vehicle mechanics in the United States and abroad were characterized using available data from published and unpublished studies. In the United States, the time-weighted-average (TWA) airborne concentration of benzene for vehicle mechanics averaged 0.01-0.05 ppm since at least the late 1970s, with maximal TWA concentrations ranging from 0.03 to 0.38 ppm. Benzene exposures were notably lower in the summer than winter and in the Southwest compared to other geographic regions, but significantly higher during known gasoline-related tasks such as draining a gas tank or changing a fuel pump or fuel filter. Measured airborne concentrations of benzene were also generally greater for vehicle mechanics in other countries, likely due to the higher benzene content of gasoline and other factors. Short-term airborne concentrations of benzene frequently exceeded 1 ppm during gasoline-related tasks, but remained below 0.2 ppm for tasks involving other petroleum-derived products such as carburetor and brake cleaner or parts washer solvent. Application of a two-zone mathematical model using reasonable input values from the literature yielded predicted task-based benzene concentrations during gasoline and aerosol spray cleaner scenarios similar to those measured for vehicle mechanics during these types of tasks. When evaluated using appropriate biomarkers, dermal exposures were found to contribute little to total benzene exposures for this occupational group. Available data suggest that vehicle mechanics have not experienced significant exposures to benzene in the workplace, except perhaps during short-duration gasoline-related tasks, and full-shift benzene exposures have remained well below current and contemporaneous occupational exposure limits. These findings are consistent with epidemiology studies of vehicle mechanics, which have not demonstrated an increased risk of benzene-induced health effects in this cohort of workers. Data and information presented here may be used to assess past, current, or future exposures and risks to benzene for vehicle mechanics who may be exposed to gasoline or other petroleum-derived products.

A case-control study of long-term exposure to ambient volatile organic compounds and lung cancer in Toronto, Ontario, Canada

Few studies have investigated associations between nonoccupational exposure to ambient volatile organic compounds and lung cancer. We conducted a case-control study of 445 incident lung cancers and 948 controls (523 hospital, 425 general population) in Toronto, Ontario, Canada, between 1997 and 2002. Participants provided information on several risk factors, including tobacco use, secondhand exposure to cigarette smoke, obesity, and family history of cancer. Exposure to benzene, hydrocarbons, and nitrogen dioxide was estimated using land-use regression models. Exposures were linked to residential addresses to estimate exposure at the time of interview, 10 years before interview, and across past residences (time-weighted average). Logistic regression was used to estimate adjusted odds ratios. Analyses involving the population-based controls found that an interquartile-range increase in the time-weighted average benzene concentration (0.15 µg/m(3)) across previous residences was associated with lung cancer (odds ratio = 1.84, 95% confidence interval: 1.26, 2.68). Similarly, an interquartile-range increase in the time-weighted average nitrogen dioxide concentration (4.8 ppb) yielded an odds ratio of 1.59 (95% confidence interval: 1.19, 2.12). Our study suggests that long-term exposure to ambient volatile organic compounds and nitrogen dioxide at relatively low concentrations is associated with lung cancer. Further work is needed to evaluate joint relationships between these pollutants, smoking, and lung cancer.

Environmental and lifestyle factors affect benzene uptake biomonitoring of residents near a petrochemical plant

BACKGROUND

We monitored urinary benzene excretion to examine factors affecting benzene uptake in a sample of the general population living near a petrochemical plant.

METHODS

Our study population included 143 subjects: 33 petrochemical plant workers (W) with low level occupational benzene exposure; 30 residents in a small town 2 km from the plant (2kmR); 26 residents in a second small town located 2 to 4 km from the plant (4kmR); and 54 urban residents 25km from the plant (25kmR). Exposure to benzene was evaluated by personal air sampling during one work-shift for the W group, and from 8.00 to 20:00 for general population subgroups, and by urinary benzene (BEN-U).

RESULTS

Median airborne benzene exposure was 25, 9, 7 and 6 μg/m(3) benzene among the W, 2kmR, 4kmR, and 25kmR subgroups, respectively; the highest level was found among the workers, while there was no significant difference among the other groups. Median BEN-U was 2 to 14-fold higher in smokers compared to non-smokers; among non-smokers BEN-U was the highest in W (median 236 ng/L), and lower in the 2kmR (48 ng/L) and 4kmR (63 ng/L) subgroups than in the 25kmR (120 ng/L) subgroup. A multiple linear regression analysis, explaining up to 73% of BEN-U variability, confirmed that active smoking and airborne benzene most strongly affected BEN-U. Among the non-smoking, non-occupationally exposed study subjects, a positive association was found between BEN-U and the distance of residence from the plant. This association was explained by increased exposure to urban traffic emissions in the study group residing at a greater distance from the plant. Environmental tobacco smoke had a marginally positive role.

CONCLUSION

Among factors affecting benzene uptake in non-occupationally exposed individuals, urban residence contributes to benzene exposure more than residing in close proximity to a petrochemical plant.

Hexavalent chromium compounds in the workplace: assessing the extent and magnitude of occupational exposure in Italy

Hexavalent chromium (Cr(VI)) compounds have been classified as carcinogenic to humans. This study evaluates the extent and magnitude of occupational exposures to Cr(VI) in Italy. Data were collected from exposure registries of companies compulsorily notified by the National Workers' Compensation Authority. Each measurement was characterized by economic activity sector, work force size, worker personal data, job description, year of measurement, and level of exposure. Descriptive statistical analysis was carried out on the retrieved information. The number of workers potentially exposed was estimated for some industrial sectors. A mixed-effects model was adopted to evaluate the association between exposure variables and exposure concentrations. Over 8400 measurements of Cr(VI) exposures were selected from the database of registries for 1996-2009. Most exposures occurred in the manufacture of fabricated metal products (>50%), and the occupational group most frequently measured was metal finishing-, plating- and coating-machine operators (>52%). Measurements were associated with various Cr(VI) compounds, including chromium trioxide, potassium dichromate, sodium dichromate, strontium chromate, and zinc chromate. Cr(VI) exposure has decreased in more recent years, and the fixed-effects (Cr(VI) compound, activity sector, size and location of the facility, job category, and year of measurement of the final statistical model explained more than 70% of the variance in the observed exposure data. This study summarized data recorded in the Italian occupational exposure database and identified specific exposure patterns to Cr(VI). The mean level of exposure to Cr(VI) was 30.41 μg/m³, and 50,118 workers were estimated at exposure risk in the selected industrial sectors. Systematic recording of occupational exposures is a source of data that allows recognition of high risk situations and improvements in exposure assessment for epidemiologic studies.