Full-shift Personal Exposure Research Articles

Occupational exposure to inhalable pathogenic microorganisms in waste sorting

This study assessed microorganisms in personal inhalable work air samples aiming to identify potential human pathogens, and correlate exposure to adverse health outcomes in waste workers. Full-shift personal exposure was measured in six different waste sorting plants. Microbial concentrations in inhalable air samples were analysed using MALDI-TOF MS for cultivable, and next generation sequencing (NGS) for non-cultivable microorganisms. Concentrations of bacterial and fungal CFUs varied substantially within and between waste sorting plants, ranging from no identifiable organisms to a maximum concentration in the order of 105 CFU/m3. Bacillus and Staphylococcus were among the most abundant bacterial genera, whilst fungal genera were dominated by Aspergillus and Penicillium. Approximately 15% of all identified species were human pathogens classified in risk group 2, whereas 7% belonged to risk group 1. Furthermore, significant correlations between concentrations of fungi in risk group 1 and self-reported adverse symptoms, such as wheezing were identified in exposed workers. The combination of culture-based methods and NGS facilitated the investigation of infectious microbial species with potential pathophysiological properties as well as non-infectious biological agents in inhalable work air samples and thereby contributed to the risk assessment of occupational exposure in waste sorting.

Noise Exposure and Hearing Loss among Workers at a Hammer Forge Company.

The National Institute for Occupational Safety and Health (NIOSH) evaluated continuous and impact noise exposures and hearing loss among workers at a hammer forge company. Full-shift personal noise exposure measurements were collected on forge workers across 15 different job titles; impact noise characteristics and one-third octave band noise levels were assessed at the forge hammers; and 4,750 historic audiometric test records for 483 workers were evaluated for hearing loss trends. Nearly all workers' noise exposures exceeded regulatory and/or recommended exposure limits. Workers working in jobs at or near the hammers had full-shift time-weighted average noise exposures above 100 decibels, A-weighted. Impact noise at the hammers reached up to 148 decibels. Analysis of audiometric test records showed that 82% of workers had experienced a significant threshold shift, as defined by NIOSH, and 63% had experienced a standard threshold shift, as defined by the Occupational Safety and Health Administration (OSHA). All workers with an OSHA standard threshold shift had a preceding NIOSH significant threshold shift which occurred, on average, about 7 years prior. This evaluation highlights forge workers' exposures to high levels of noise, including impact noise, and how their hearing worsened with age and length of employment.

Hearing Impairment in Municipal Refuse and Glass Recycling Collection Operatives.

Several international regulatory bodies and researchers have identified employees in the municipal refuse and recycling industry as potentially at risk of noise induced hearing loss. Whilst materials recycling facilities have been subject to research regarding the health effects of hazardous exposures, the roadside recycling collection aspects of the industry has been identified as requiring further investigation. The requirement for characterization of such risk has been increased in the European Union by legislation that has led to increased rates of municipal recycling in the waste disposal industry. In particular, the introduction of glass recycling collection rounds over recent years, alongside long-established refuse collection activities, has given rise to possible further increased levels of industrial noise exposure, beyond that of refuse collection alone. This cross-sectional study describes hearing threshold categorization in 201 male full-time refuse collection workers, most of whom had many years of employment in municipal refuse collection, and all of whom, in the 3-4 years preceding the study, had commenced a work pattern of alternating weeks of municipal glass recycling collection and refuse collection. During this period there was no compulsory use of personal hearing protective equipment. No excess of hearing loss was found in this group, irrespective of years in refuse collection duties or when compared with those studied with additional responsibilities as a driver of refuse wagons (a task not considered to lead to excessive noise exposure). Further research into hearing loss in such employees is merited, given the short time period of exposure to noise from glass collection, but the possible benefit of undertaking detailed full shift personal noise exposure in this group is proposed.

Biomonitoring of Benzene and Effect of Wearing Respirators during an Oil Spill Field Trial at Sea

The main aim of this study was to assess the biological uptake of benzene and polycyclic aromatic hydrocarbons (PAHs) for subjects exposed to fresh crude oil released at sea. The study included 22 subjects participating in an 'oil-on-water' field trial in the North Sea. Over 2 consecutive days, there were six releases with two different types of fresh crude oils. Exposed subjects (n = 17) were either located in small, open-air boats downwind and close to the released oil (<50 m) or on the main deck of two large vessels further from the released oil (100-200 m). Subjects assumed to be unexposed (n = 5) were located indoors on the command bridge of either vessel. Full-shift personal benzene exposure was monitored with passive thermal desorption tubes (ATD-tubes) packed with Tenax TA and subsequent gas chromatographic analysis. Urine samples were collected before and after work-shift on both days and analyzed for urinary markers of benzene [(S-phenylmercapturic acid (SPMA)] and PAHs [1-hydroxypyrene (1-OH)]. Information about the use of personal protective equipment, smoking habits, location, work tasks, and length of work-shift were recorded by a questionnaire. Subjects located in the small boats downwind and close to the released oil were exposed to relatively high concentrations of benzene (arithmetic mean = 0.2 ppm, range 0.002-1.5 ppm) compared to the occupational exposure limits (OELs) for 8 h (1 ppm) and 12 h (0.6 ppm). Although respirators were available to all exposed subjects, SPMA was detected in post-shift urine (0.5-3.3 µmol mol-1) of five exposed subjects reporting not wearing respirators, all located in the small boats downwind and close to the released oil. For exposed subjects wearing respirators (n = 12), the post-shift urinary SPMA was below the detection limit (0.8 µmol mol-1) even when the benzene exposure exceeded the OELs. Urinary levels of PAH were within the reference range of what is considered as background levels (<0.4 µmol mol-1). During the initial stages of a bulk oil spill at sea, when the evaporation of benzene is at its highest, it is important to use appropriate respirators to prevent biological uptake of benzene.

Evaluation of 1-Nitropyrene as a Surrogate Measure for Diesel Exhaust.

We investigated the viability of particle bound 1-nitropyrene (1-NP) air concentration measurements as a surrogate of diesel exhaust (DE) exposure, as compared with industry-standard elemental carbon (EC) and total carbon (TC) measurements. Personal exposures are reported for 18 employees at a large underground metal mine during four different monitoring campaigns. Full-shift personal air exposure sampling was conducted using a Mine Safety and Health Administration (MSHA) compliant diesel particulate matter (DPM) impactor cassette downstream of a GS-1 cyclone pre-selector. Each DPM filter element was analyzed for EC and organic carbon (OC) using NIOSH Method 5040. After EC and OC analysis, the remaining portion of each DPM filter was analyzed for 1-NP using liquid chromatography tandem mass spectrometry (LC/MS/MS). We observed high correlations between the quantiles of 1-NP and EC exposures across 10 different work shift task groups (r = 0.87 to 0.96), and a linear relationship with a slope between 6.0 to 6.9 pg 1-NP per µg EC. However, correlation between 1-NP and EC was weak (r =0.34) for the 91 individual sample pairs due to low EC concentrations and possible heterogeneity of DE composition. While both 1-NP and EC differentiated between high and low exposure groups categorized by job location, measurements of 1-NP, but not EC further differentiated between specific job activities. Repeated measurements on individual subjects verified the relationship between 1-NP and EC and demonstrated substantial within-subject variability in exposure. The detection limit of TC air concentration ranged between 18 and 28 µg m-3 and was limited by OC contamination of the quartz filters in the MSHA compliant DPM samplers.

Oil Spill Field Trial at Sea: Measurements of Benzene Exposure

Characterize personal exposure to airborne hydrocarbons, particularly carcinogenic benzene, during spill of two different fresh crude oils at sea. The study included 22 participants taking part in an «oil on water» field trial in the North Sea. Two types of fresh crude oils (light and heavy) were released six times over two consecutive days followed by different oil spill response methods. The participants were distributed on five boats; three open sampling boats (A, B, and C), one release ship (RS), and one oil recovery (OR) vessel. Assumed personal exposure was assessed a priori, assuming high exposure downwind and close to the oil slick (sampling boats), low exposure further downwind (100-200 m) and upwind from the oil slick (main deck of RS and OR vessel), and background exposure indoors (bridge of RS/OR vessel). Continuous measurements of total volatile organic compounds in isobutylene equivalents were performed with photoionization detectors placed in all five boats. Full-shift personal exposure to benzene, toluene, ethylbenzene, xylenes, naphthalene, and n-hexane was measured with passive thermal desorption tubes. Personal measurements of benzene, averaged over the respective sample duration, on Day 1 showed that participants in the sampling boats (A, B, and C) located downwind and close to the oil slick were highest exposed (0.14-0.59 ppm), followed by participants on the RS main deck (0.02-0.10 ppm) and on the bridge (0.004-0.03 ppm). On Day 2, participants in sampling boat A had high benzene exposure (0.87-1.52 ppm) compared to participants in sampling boat B (0.01-0.02 ppm), on the ships (0.06-0.10 ppm), and on the bridge (0.004-0.01 ppm). Overall, the participants in the sampling boats had the highest exposure to all of the compounds measured. The light crude oil yielded a five times higher concentration of total volatile organic compounds in air in the sampling boats (max 510 ppm) than the heavy crude oil (max 100 ppm) but rapidly declined to <20 ppm within 24 min after release of oil, indicating short periods of exposure. The personal exposure to benzene downwind and close to the oil slick during spills of light crude oil was relatively high, with concentration levels approaching the occupational exposure limits for several participants. For bulk spill scenarios like in this study, cleanup should not be initiated the first 30-60 min to allow for evaporation, while appropriate personal protective equipment should be used in continuous spills when working downwind and close to the oil slick.

Retrospective benzene exposure assessment for a multi-center case-cohort study of benzene-exposed workers in China.

Quality of exposure assessment has been shown to be related to the ability to detect risk of lymphohematopoietic disorders in epidemiological investigations of benzene, especially at low levels of exposure. We set out to build a statistical model for reconstructing exposure levels for 2898 subjects from 501 factories that were part of a nested case-cohort study within the NCI-CAPM cohort of more than 110,000 workers. We used a hierarchical model to allow for clustering of measurements by factory, workshop, job, and date. To calibrate the model we used historical routine monitoring data. Measurements below the limit of detection were accommodated by constructing a censored data likelihood. Potential non-linear and industry-specific time-trends and predictor effects were incorporated using regression splines and random effects. A partial validation of predicted exposures in 2004/2005 was performed through comparison with full-shift measurements from an exposure survey in facilities that were still open. Median cumulative exposure to benzene at age 50 for subjects that ever held an exposed job (n=1175) was 509 mg/m(3) years. Direct comparison of model estimates with measured full-shift personal exposure in the 2004/2005 survey showed moderate correlation and a potential downward bias at low (<1 mg/m(3)) exposure estimates. The modeling framework enabled us to deal with the data complexities generally found in studies using historical exposure data in a comprehensive way and we therefore expect to be able to investigate effects at relatively low exposure levels.

Effectiveness of a Multidimensional Randomized Control Intervention to Reduce Quartz Exposure Among Construction Workers.

There is little evidence with respect to the effectiveness of intervention programs that focus on the reduction of occupational quartz exposure in the construction industry. This article evaluates the effectiveness of a multidimensional intervention which was aimed at reducing occupational quartz exposure among construction workers by increasing the use of technical control measures. Eight companies participating in the cluster randomized controlled trial were randomly allocated to the intervention (four companies) or control condition (four companies). The multidimensional intervention included engineering, organizational, and behavioural elements at both organizational and individual level. Full-shift personal quartz exposure measurements and detailed observations were conducted before and after the intervention among bricklayers, carpenters, concrete drillers, demolishers, and tuck pointers (n = 282). About 59% of these workers measured at baseline were reassessed during follow-up. Bayesian hierarchical models were used to evaluate the intervention effect on exposure levels. Concrete drillers in the intervention group used technical control measures, particularly water suppression, for a significantly greater proportion of the time spent on abrasive tasks during follow-up compared to baseline (93 versus 62%; P < 0.05). A similar effect, although not statistically significant, was observed among demolishers. A substantial overall reduction in quartz exposure (73 versus 40% in the intervention and control group respectively; P < 0.001) was observed for concrete drillers, demolishers, and tuck pointers. The decrease in exposure in the intervention group compared to controls was significantly larger for demolishers and tuck pointers, but not for concrete drillers. The observed effect could at least partly be explained by the introduced interventions; the statistically significant increased use of control measures among concrete drillers explains the observed effect to some extent in this job category only. Sensitivity analyses indicated that the observed decrease in exposure may also partly be attributable to changes in work location and abrasiveness of the tasks performed. Despite the difficulties in assessing the exact magnitude of the intervention, this study showed that the structured intervention approach at least partly contributed to a substantial reduction in quartz exposure among high exposed construction workers.

Evaluation of Potential Noise Exposures in Hospital Operating Rooms

The National Institute for Occupational Safety and Health received a health hazard evaluation request from West Virginia University Hospital, Morgantown, to evaluate noise exposures from surgical instruments in the OR. Four surgical technologists, four RNs, and one surgeon wore noise dosimeters to measure full-shift personal noise exposures during two days while they performed typical daily activities. Measurements did not exceed Occupational Safety and Health Administration or National Institute for Occupational Safety and Health noise exposure limits; however, area sound level measurements indicated that some intermittent activities can generate sound levels above 90 A-weighted decibels. Examples include surgery preparation, drilling or noise from other powered surgical instruments during surgeries, and clean up. Preventive maintenance of powered surgical instruments can reduce noise exposures, and noise output should be considered when selecting replacement instruments. Keeping music at a low level and using hearing protection are other interventions to consider to improve noise levels in an OR.

Exposure Assessment in Auto Collision Repair Shops

Workers in auto collision shops are exposed to a variety of chemical and physical hazards. Previous studies have focused on measuring levels of isocyanates, but little is known about exposures to dust, noise, and solvents. In preparation for an intervention effectiveness study in small collision repair businesses, sampling was conducted on 3 consecutive days in four representative businesses with three to seven employees. Full-shift and task-specific exposures were measured for dust and solvents (for operations other than painting and spray gun cleaning). Full-shift personal exposures and tool-specific noise levels were also evaluated. Samples of banded earplugs were distributed to employees and feedback was collected after 1 week of wear time. Dust and solvent exposures did not exceed the OSHA PELs. Noise exposure doses were below the OSHA PEL; however, 4 of the 18 measurements were in excess of the ACGIH® threshold limit value. The majority of tools generated noise levels above 85 dBA. Air guns, wrenches, cutoff wheels, and air drills generated noise levels with the 5th percentile above 90 dBA. Mean noise levels generated by hammers, grinders, and ratchets were also above 95 dBA. Three pairs of banded earplugs had the best reviews in terms of comfort of use. This study was conducted during a time when all shops reported relatively low production levels. Noise exposure results suggest that it is likely that technicians’ 8-hr time-weighted average exposures may be in excess of 85 dBA during periods of higher production, but exposures to dust and solvents are unlikely to approach OSHA exposure limits. These pilot test results will be useful when developing recommendations and technical assistance materials for health and safety interventions in auto collision repair businesses. [Supplementary materials are available for this article. Go to the publisher's online edition of the Journal of Occupational and Environmental Hygiene for the following free supplemental resource: a PDF containing a table on employee feedback on seven hearing band models, an example of an HP feedback card, a table showing a tool for selecting the solvents to be analyzed for area samples, a table containing MSDS and sample information for degreasing compounds, additional information for degreasing operations, an excerpt from the discussion with the AssayTech lab manager, and an image from the paint mixing room that returned the highest styrene and acetone concentrations.]

UK Smoke-Free Legislation: Changes in PM&lt;sub&gt;2.5&lt;/sub&gt; Concentrations in Bars in Scotland, England, and Wales

Evaluate the effect of smoke-free legislation on fine particulate [particulate matter <2.5 microm in diameter (PM(2.5))] air pollution levels in bars in Scotland, England, and Wales. Air quality was measured in 106 randomly selected bars in Scotland, England, and Wales before and after the introduction of smoking restrictions. PM(2.5) concentrations were measured covertly for 30-min periods before smoke-free legislation was introduced, again at 1-2 months post-ban (except Wales) and then at 12-months post-baseline (except Scotland). In Scotland and England, overt measurements were carried out to assess bar workers' full-shift personal exposures to PM(2.5). Postcode data were used to determine socio-economic status of the bar location. PM(2.5) levels prior to smoke-free legislation were highest in Scotland (median 197 microg m(-3)), followed by Wales (median 184 microg m(-3)) and England (median 92 microg m(-3)). All three countries experienced a substantial reduction in PM(2.5) concentrations following the introduction of the legislation with the median reduction ranging from 84 to 93%. Personal exposure reductions were also within this range. There was evidence that bars located in more deprived postcodes had higher PM(2.5) levels prior to the legislation. Prior to legislation PM(2.5) concentrations within bars across the UK were much higher than the 65 microg m(-3) 'unhealthy' threshold for outdoor air quality as set by the US Environmental Protection Agency. Concentrations in Scottish and Welsh bars were, on average, two or more times greater than in English bars for which seasonal influences may be responsible. Legislation in all three countries produced improvements in indoor air quality that are consistent with other international studies.

Personal exposure to inhalable cement dust among construction workers

A case study was carried out in 2006-2007 to assess the actual cement dust exposure among construction workers involved in a full-scale construction project and as a comparison among workers involved in various stages of cement and concrete production. Full-shift personal exposure measurements were performed for several job types. Inhalable dust and cement dust (based on analysis of elemental calcium) concentrations were determined. Inhalable dust exposures at the construction site ranged from 0.05 to 34 mg/m3, with a mean concentration of 1.0 mg/m3. For inhalable cement dust mean exposure was 0.3 mg/m3 (range 0.02-17 mg/m3). Reinforcement and pouring workers had the lowest average concentrations. Inhalable dust levels in the ready-mix and pre-cast concrete plants were, on average, below 0.5 mg/m3 for inhalable dust and below 0.2 mg/m3 for inhalable cement dust. Highest dust concentrations were measured in cement production, particularly during cleaning tasks (inhalable dust GM=55 mg/m3; inhalable cement dust GM=33 mg/m3) at which point the workers wore personal protective equipment. Elemental measurements showed highest but very variable cement percentages in the cement plant and very low percentages of cement during reinforcement work and pouring.

Personal exposure to inhalable cement dust among construction workers

Objective- A case study was carried out to assess cement dust exposure and its determinants among construction workers and for comparison among workers in cement and concrete production.Methods- Full-shift personal exposure measurements were performed and samples were analysed for inhalable dust and its cement content. Exposure variability was modelled with linear mixed models.Results- Inhalable dust concentrations at the construction site ranged from 0.05 to 34 mg/m(3), with a mean of 1.0 mg/m(3). Average concentration for inhalable cement dust was 0.3 mg/m(3) (GM; range 0.02-17 mg/m(3)). Levels in the ready-mix and pre-cast concrete plants were on average 0.5 mg/m(3) (GM) for inhalable dust and 0.2 mg/m(3) (GM) for inhalable cement dust. Highest concentrations were measured in cement production, particularly during cleaning tasks (inhalable dust GM = 55 mg/m(3); inhalable cement dust GM = 33 mg/m(3)) at which point the workers wore personal protective equipment. Elemental measurements showed highest but very variable cement percentages in the cement plant and very low percentages during reinforcement work and pouring. Most likely other sources were contributing to dust concentrations, particularly at the construction site. Within job groups, temporal variability in exposure concentrations generally outweighed differences in average concentrations between workers. 'Using a broom', 'outdoor wind speed' and 'presence of rain' were overall the most influential factors affecting inhalable (cement) dust exposure.Conclusion- Job type appeared to be the main predictor of exposure to inhalable (cement) dust at the construction site. Inhalable dust concentrations in cement production plants, especially during cleaning tasks, are usually considerably higher than at the construction site.

Bar Workers' Exposure to Second-Hand Smoke: The Effect of Scottish Smoke-Free Legislation on Occupational Exposure

To examine changes in bar workers' exposure to second-hand smoke (SHS) over a 12-month period before and after the introduction of Scottish smoke-free legislation on the 26 March 2006. A total of 371 bar workers were recruited from 72 bars in three cities: Aberdeen, Glasgow, Edinburgh and small towns in two rural regions (Borders and Aberdeenshire). Prior to the introduction of the smoke-free legislation, we visited all participants in their place of work and collected saliva samples, for the measurement of cotinine, together with details on work patterns, self-reported exposure to SHS at work and non-work settings and smoking history. This was repeated 2 months post-legislation and again in the spring of 2007. In addition, we gathered full-shift personal exposure data from a small number of Aberdeen bar workers using a personal aerosol monitor for fine particulate matter (PM(2.5)) at the baseline and 2 months post-legislation visits. Data were available for 371 participants at baseline, 266 (72%) at 2 months post-legislation and 191 (51%) at the 1-year follow-up. The salivary cotinine level recorded in non-smokers fell from a geometric mean of 2.94 ng ml(-1) prior to introduction of the legislation to 0.41 ng ml(-1) at 1-year follow-up. Paired data showed a reduction in non-smokers' cotinine levels of 89% [95% confidence interval (CI) 85-92%]. For the whole cohort, the duration of workplace exposure to SHS within the last 7 days fell from 28.5 to 0.83 h, though some bar workers continued to report substantial SHS exposures at work despite the legislation. Smokers also demonstrated reductions in their salivary cotinine levels of 12% (95% CI 3-20%). This may reflect both the reduction in SHS exposure at work and falls in active cigarette smoking in this group. In a small sub-sample of bar workers, full-shift personal exposure to PM(2.5), a marker of SHS concentrations, showed average reductions of 86% between baseline and 2 months after implementation of the legislation. Most bar workers have experienced very large reductions in their workplace exposure to SHS as a result of smoke-free legislation in Scotland. These reductions have been sustained over a period of 1 year.

Biological Monitoring of Benzene Exposure for Process Operators during Ordinary Activity in the Upstream Petroleum Industry

This study characterized the exposure of crude oil process operators to benzene and related aromatics during ordinary activity and investigated whether the operators take up benzene at this level of exposure. We performed the study on a fixed, integrated oil and gas production facility on Norway's continental shelf. The study population included 12 operators and 9 referents. We measured personal exposure to benzene, toluene, ethylbenzene and xylene during three consecutive 12-h work shifts using organic vapour passive dosimeter badges. We sampled blood and urine before departure to the production facility (pre-shift), immediately after the work shift on Day 13 of the work period (post-shift) and immediately before the following work shift (pre-next shift). We also measured the exposure to hydrocarbons during short-term tasks by active sampling using Tenax tubes. The arithmetic mean exposure over the 3 days was 0.042 ppm for benzene (range <0.001-0.69 ppm), 0.05 ppm for toluene, 0.02 ppm for ethylbenzene and 0.03 ppm for xylene. Full-shift personal exposure was significantly higher when the process operators performed flotation work during the shift versus other tasks. Work in the flotation area was associated with short-term (6-15 min) arithmetic mean exposure to benzene of 1.06 ppm (range 0.09-2.33 ppm). The concentrations of benzene in blood and urine did not differ between operators and referents at any time point. When we adjusted for current smoking in regression analysis, benzene exposure was significantly associated with the post-shift concentration of benzene in blood (P = 0.01) and urine (P = 0.03), respectively. Although these operators perform tasks with relatively high short-term exposure to benzene, the full-shift mean exposure is low during ordinary activity. Some evidence indicates benzene uptake within this range of exposure.

Exposure to Ammonia and Acute Respiratory Effects in a Urea Fertilizer Factory

Personal exposures to ammonia and acute respiratory effects were determined in workers at a urea fertilizer factory in Bangladesh. Full-shift personal exposure to ammonia was measured using a PAC III direct reading instrument and Drager diffusion tubes. Respiratory symptoms were elicited by a questionnaire study (n = 113), and preshift and postshift lung function (FVC, FEV1, and PEFR) were tested using spirometry (n = 88). Urea plant workers had higher mean exposure to ammonia and prevalence of acute respiratory symptoms than did workers in the ammonia plant. The symptoms with highest prevalence in the urea plant were chest tightness (33%) and cough (28%). FVC and FEV1 decreased significantly across the work shift among urea plant workers. The higher level of exposure to ammonia in the urea plant was associated with an increased prevalence of respiratory symptoms and an acute decline in lung function.

Assessment of potential hazards during the process of house building in Estonia

The aim of this study was to evaluate new working conditions in the construction industry in Estonia. Three construction sites were investigated: a dwelling house at the stage of renovation, a warehouse at the stage of excavation and preparation work, and a hotel, where we examined the working conditions of the finishers. Microclimate: air temperature, relative humidity and air velocity were determined at every workplace. Full-shift personal exposure measurements of dust and gas exposure were performed among 97 construction workers in breathing zone air. The concentration of lead in the air was analysed by AAS. Vapours of benzene, styrene and toluene concentrations were determined by gas chromatography. The noise level was measured with the help of the sound-level meter at every workplace. All microclimatic indices were sometimes below or above exposure standards for indoor work. High levels of airborne dust and increased concentrations of lead were observed during repair work. Low concentrations of organic solvents in the air were determined when using paints and some synthetic substances. The noise level exceeded the permitted limit when an excavator and powerful electric appliances were used. A questionnaire determined the prevalence of subjectively experienced musculoskeletal strain in 30% of workers. The working conditions in the construction industry in Estonia are approaching European level. However, it is necessary to improve working conditions permanently by the use of new harmless materials, personal protective equipment, and through influencing worker health by permanent education and medical watch. We consider that questionnaires are very important in the control of the work environment, in subjective health assessments, and as a source of useful proposals to improve working conditions.

Follow up study of haematological effects in workers exposed to 2-methoxyethanol

Aims: To examine the association between 2-methoxyethanol (2-ME) exposure and haematological effects, as well as the recovery from these haematological effects with continuous reduction in exposure to 2-ME. Methods: Twenty...

Pneumoconiosis and Exposure to Quartz-Containing Dust in the Construction Industry

Construction workers are potentially at risk for pneumoconiosis due to exposure to high levels of quartz-containing dust. Studies on quartz and dust exposure in the construction industry are scarce and little is known about the toxic potency. An additional problem is the potential heterogeneity of the toxic potency due to differences in materials used in this industry. In this study we have made an attempt to characterize dust and quartz exposure as part of a cross-sectional study on pneumoconiosis among construction workers. Construction workers (n = 1335) were studied for quartz dust-related radiographic abnormalities and lung function changes. Full shift personal respirable exposure measurements (n = 68) were performed for certain job titles included in the cross-sectional study. For a more precise characterization of the dust, several samples were studied by scanning electron microscopy and X-ray diffraction. A mixed dust type of pneumoconiosis (ILO category ≥1/1, irregular opacities) was observed in 2.9% of the construction workers studied. Exposure measurements showed quartz levels between 0.002 and 3.77 mg/m 3 . SEM analysis showed that most particles consisted of silica and that dusts sampled during different tasks had different size distributions. In all samples, particle size ranged from 200–300 nm to 5–10 mm. The risk for pneumoconiosis among construction workers is evident, but a clear-cut exposure–response relationship is hard to define because of heterogeneity in dust exposure levels, heterogeneity in composition of the dusts and possible modification of the toxicity of quartz by other factors present in the dusts.

Characterization of Extremely Low Frequency Magnetic Field Exposures of Office Workers

Abstract The purpose of this study is to present results of an extremely low frequency magnetic field exposure assessment performed in a large office building environment. The extremely low frequency magnetic field assessment strategy included an evaluation of full-shift personal exposure for building occupants, a determination of average work area magnetic fields, and magnetic field characterizations of sources within each work area. An employee questionnaire regarding daily utilization patterns of workplace magnetic field sources was also used to help interpret exposure information. Magnetic field exposures were determined using EMDEX magnetic field exposure meters. For personal magnetic field characterization, each participant wore the monitor for a full shift, and office area magnetic fields were determined as the average of five equally spaced measurements. In situ source characterization included measuring magnetic fields at 30 and 50 cm from pieces of electrical equipment. 259 employees in the buil...