Area Air Samples Research Articles

Distribution and Prevalence of Airborne Microorganisms in Three Commercial Poultry Processing Plants

Airborne microbial contaminants and indicator organisms were monitored within three poultry processing plants (plants A, B, and C). In total, 15 cubic feet (c.f.) of air was sampled per location during 15 visits to each plant and quantitatively analyzed for total mesophilic and psychrophilic aerobic counts, thermophilic campylobacters, Escherichia coli, and Enterobacteriaceae. The prevalence of Salmonella spp. in air samples was also evaluated. Significant reductions in total aerobic counts were observed between defeathering and evisceration areas of the three plants (P < 0.05). Mesophilic plate counts were highest in the defeathering areas of all plants compared to equivalent psychrophilic plate counts. Enterobacteriaceae counts were highest in the defeathering areas of all three plants with counts of log10 1.63, 1.53, and 1.18 CFU/15 c.f. recovered in plants A, B, and C, respectively. E. coli enumerated from air samples in the defeathering areas exhibited a similar trend to those obtained for Enterobacteriaceae with log10 1.67, 1.58, and 1.18 CFU for plants A, B, and C, respectively. Thermophilic campylobacters were most frequently isolated from samples in the defeathering areas followed by the evisceration areas. The highest mean counts of the organism were observed in plant A at 21 CFU/15 c.f. sample with plants B and C at 9 and 8 CFU/sample, respectively. With the exception of low levels of Enterobacteriaceae recovered from samples in the on-line air chill in plant A, E. coli, Enterobacteriaceae, or Campylobacter spp. were not isolated from samples in postevisceration sites in any of the plants examined. Salmonella spp. were not recovered from any samples during the course of the investigation.

A Statistical Evaluation of Asbestos Air Concentrations

Both area and personal air samples collected during an asbestos abatement project were matched and statistically analysed. Among the many parameters studied were fibre concentrations and their variability. Mean values for area and personal samples were 0.005 and 0.024 f·cm^–3 of air, respectively. Summary values for area and personal samples suggest that exposures are low with no single exposure value exceeding the current OSHA TWA value of 0.1 f·cm^–3 of air. Within- and between-worker analysis suggests that these data are homogeneous. Comparison of within- and between-worker values suggests that the exposure source and variability for abatement are more related to the process than individual practices. This supports the importance of control measures for abatement. Study results also suggest that area and personal samples are not statistically related, that is, there is no association observed for these two sampling methods when data are analysed by correlation or regression analysis. Personal samples were statistically higher in concentration than area samples. Area sampling cannot be used as a surrogate exposure index for asbestos abatement workers.

A Statistical Evaluation of Asbestos Air Concentrations

Both area and personal air samples collected during an asbestos abatement project were matched and statisti cally analysed. Among the many parameters studied were fibre concentrations and their variability. Mean values for area and personal samples were 0.005 and 0.024 f.cm -3 of air, respectively. Summary values for area and personal samples suggest that exposures are low with no single exposure value exceeding the current OSHA TWA value of 0.1 f.cm-3 of air. Within- and between-worker analysis suggests that these data are homogeneous. Comparison of within- and between- worker values suggests that the exposure source and variability for abatement are more related to the process than individual practices. This supports the importance of control measures for abatement. Study results also suggest that area and personal samples are not statisti cally related, that is, there is no association observed for these two sampling methods when data are analysed by correlation or regression analysis. Personal samples were statistically higher in concentration than area sam ples. Area sampling cannot be used as a surrogate expo sure index for asbestos abatement workers.

Asbestos fiber release from the brake pads of overhead industrial cranes.

The purpose of this evaluation was to determine the actual contribution of airborne asbestos fibers to the work environment from the operation of overhead cranes and hoists that use asbestos composition brake pads. The evaluation was conducted in a working manufacturing facility. Other potential sources of asbestos were accounted for by visual inspection and background air monitoring. An overhead crane assembly comprised of a trolley and two hoists was employed for this study. The crane was operated for two consecutive eight-hour shifts representative of a heavy-duty cycle. Forty-four personal and area air samples were collected during the assessment. Asbestos fibers were analyzed for by phase contrast (NIOSH 7400), and transmission electron (NIOSH 7402) microscopy methods. Eight-hour time-weighted average (TWA) asbestos fiber concentrations ranged from < 0.005 to 0.011 fibers/cc (PCM), and < 0.0026 to < 0.0094 f/cc (TEM). There were no asbestos fibers detected by the TEM method from air samples collected during the operation of the cranes.

An Australian Study to Evaluate Worker Exposure to Chrysotile in the Automotive Service Industry

A study was conducted in Sydney, Australia, in 1996 to investigate the current exposure levels, control technologies, and work practices in five service garages (four car and one bus), three brake bonding workshops, and one gasket processing workshop. This study formed part of the assessment of chrysotile as a priority existing chemical under the Australian National Industrial Chemicals Notification and Assessment Scheme. A total of 68 (11 personal and 57 area) air samples were collected, in accordance with the Australian standard membrane filter method. Fiber concentrations were determined by the traditional phase contrast microscopy (PCM) method and 16 selected samples were analyzed by the more powerful transmission electron microscopy (TEM). Chrysotile exposure of car mechanics measured by PCM was typically below the reportable detection limit of 0.05 f/mL, irrespective of whether disc brake, drum brake, or clutch was being serviced. These low levels can be attributed to the wet cleaning or aerosol spray methods used in recent years to replace the traditional compressed air jet cleaning. In the three brake shoe relining workshops, task-specific exposure reached up to 0.16 f/mL in the processes of cutting and radius grinding. TEM results were generally higher, due to its higher resolution power. The median diameter on samples taken from the service garages (passenger cars), as determined by TEM, was 0.5-1.0 micron; and was between 0.2-0.5 micron for the brake bonding and gasket processing workshops, while that for the bus service depot was 0.1-0.2 micron. Most of the respirable fibers (84%, mainly forsterite) from the bus service depot were below 0.2 micron in diameter which is the resolution limit of PCM. In the brake bonding and gasket cutting workshops, 34 percent and 44 percent of the chrysotile fibers were below 0.2 micron in diameter.

Ultrasonic extraction and field-portable anodic stripping voltammetry for the determination of lead in workplace air samples.

An on-site, field-portable analytical method for the determination of lead in workplace air samples, based on the use of ultrasonic extraction and anodic stripping voltammetry (ASV), was evaluated. Workplace air samples were obtained using a standard method involving particulate collection onto mixed cellulose ester membrane filters. Samples were collected at work sites where airborne particulates were generated from the abrasive blasting of lead-containing paint on highway bridges. Ultrasonic extraction (UE) of air filter samples in diluted nitric acid, followed by portable ASV, was used for the determination of lead. Also, performance evaluation samples consisting of reference materials of known lead concentration were subjected to the UE-ASV procedure for lead determination. Confirmatory analyses of the air filters and performance evaluation samples subjected to the UE-ASV lead measurement method were conducted by hotplate digestion in concentrated nitric acid and 30% hydrogen peroxide, followed by inductively coupled plasma-atomic emission spectrometric (ICP-AES) determination of lead. Recoveries of lead from performance evaluation materials (when using the UE-ASV method) were found to be quantitative. The performance of the UE-ASV method for lead in air filters was found to be acceptable, as evaluated by comparison with results from hotplate strong acid digestion followed by ICP-AES analysis. Based on the results of this study, the ultrasonic extraction/portable ASV procedure demonstrates potential for the on-site determination of lead in personal breathing zone and area air samples.

Ultrasonic Extraction and Field-Portable Anodic Stripping Voltammetry for the Determination of Lead in Workplace Air Samples

An on-site, field-portable analytical method for the determination of lead in workplace air samples, based on the use of ultrasonic extraction and anodic stripping voltammetry (ASV), was evaluated. Workplace air samples were obtained using a standard method involving particulate collection onto mixed cellulose ester membrane filters. Samples were collected at work sites where airborne particulates were generated from the abrasive blasting of lead-containing paint on highway bridges. Ultrasonic extraction (UE) of air filter samples in diluted nitric acid, followed by portable ASV, was used for the determination of lead. Also, performance evaluation samples consisting of reference materials of known lead concentration were subjected to the UE-ASV procedure for lead determination. Confirmatory analyses of the air filters and performance evaluation samples subjected to the UE-ASV lead measurement method were conducted by hotplate digestion in concentrated nitric acid and 30% hydrogen peroxide, followed by inductively coupled plasma-atomic emission spectrometric (ICP-AES) determination of lead. Recoveries of lead from performance evaluation materials (when using the UE-ASV method) were found to be quantitative. The performance of the UE-ASV method for lead in air filters was found to be acceptable, as evaluated by comparison with results from hotplate strong acid digestion followed by ICP-AES analysis. Based on the results of this study, the ultrasonic extraction/portable ASV procedure demonstrates potential for the on-site determination of lead in personal breathing zone and area air samples.

Latex allergy: epidemiological study of 1351 hospital workers.

OBJECTIVE: To determine the prevalence of latex sensitisation among a large group of healthcare workers, study the occupational and non-occupational factors associated with latex allergy, and characterise latex exposure in...

Detection of snow‐crab antigens by air sampling of a snow‐crab production plant

We previously assessed the prevalence of occupational asthma (OA) to snow-crab in production plant workers. We also showed that this type of OA is related to immediate immunological reactivity as demonstrated by skin reactivity and increased specific IgE antibodies. However, we did not show that snow-crab antigens causing immunological reactivity and OA could be found in the air sampling in the plants atmosphere. This was the purpose of the current work. Area air samples worn by workers at four different worksites of a snow-crab producing plant were obtained on PVC filters with an SKC pump run at 1.5 L/min for 2 h. Snow-crab was being boiled and processed during the air sampling periods. Filters were analysed by RAST inhibition in a blind manner (i.e. without knowledge of the worksite where the filter originated). Eluate from one of the four sites (#2) had the highest protein concentration and yielded the highest per cent inhibition of RAST--13% inhibition with the snow-crab meat, 23% and 28% inhibition with the snow crab water RAST in two separate assays. An eluate taken from a filter at another site (#1) showed borderline reactivity (1% and 10% inhibition in two assays) whereas the two other ones and a control filter were negative. The two filters that contained snow-crab proteins were the ones nearest the boiling process, site #2 being the nearest followed by site #1. It was estimated that a 28% inhibition corresponded to approximately 8.6 micrograms of proteins and to approximately 1.5 micrograms of allergens on the filter. This study suggests that airborne snow-crab-derived proteins, released during the boiling process, are the cause of immunological reactivity and of OA to snow-crab.

Worker Exposures to Nitrosamines in a Rubber Vehicle Sealing Plant

Occupational nitrosamine exposures were measured during a National Institute for Occupational Safety and Health (NIOSH) health hazard evaluation at a rubber vehicle sealing plant. All of the 28 personal breathing zone samples had detectable concentrations of nitrosodimethylamine (NDMA), nitrosodiethylamine, nitrosopiperidine (NPIP), and nitrosomorpholine; and 27 of the 28 samples had detectable concentrations of nitrosopyrrolidine. The NDMA exposures were the highest, ranging from 0.47 to 11.44 µg/m3. The next highest exposures were to NPIP, ranging from 0.20 to 4.39 µg/m3. Several general area air samples were also collected, which revealed concentrations of NDMA ranging from 2.29 to 88.47 µg/m3 at the drills along the salt bath lines. The salt bath curing process appears to be the primary source of nitrosamine formation, and personal exposures were highest for the salt bath line operators and assistant operators. Although there are no numerical occupational nitrosamine standards in the United States to reference, the exposures in this plant were much higher than the German standard of 1 µg/m3 total nitrosamines for general industry and 2.5 µg/m3 total nitrosamines for certain processes such as vulcanization. NIOSH investigators recommended that the ventilation systems be improved to reduce the exposures to the lowest feasible concentrations until the process can be redesigned so that nitrosamines are not formed.

Worker exposures to nitrosamines in a rubber vehicle sealing plant.

Occupational nitrosamine exposures were measured during a National Institute for Occupational Safety and Health (NIOSH) health hazard evaluation at a rubber vehicle sealing plant. All of the 28 personal breathing zone samples had detectable concentrations of nitrosodimethylamine (NDMA), nitrosodiethylamine, nitrosopiperidine (NPIP), and nitrosomorpholine; and 27 of the 28 samples had detectable concentrations of nitrosopyrrolidine. The NDMA exposures were the highest, ranging from 0.47 to 11.44 micrograms/m3. The next highest exposures were to NPIP, ranging from 0.20 to 4.39 micrograms/m3. Several general area air samples were also collected, which revealed concentrations of NDMA ranging from 2.29 to 88.47 micrograms/m3 at the drills along the salt bath lines. The salt bath curing process appears to be the primary source of nitrosamine formation, and personal exposures were highest for the salt bath line operators and assistant operators. Although there are no numerical occupational nitrosamine standards in the United States to reference, the exposures in this plant were much higher than the German standard of 1 micrograms/m3 total nitrosamines for general industry and 2.5 micrograms/m3 total nitrosamines for certain processes such as vulcanization. NIOSH investigators recommended that the ventilation systems be improved to reduce the exposures to the lowest feasible concentrations until the process can be redesigned so that nitrosamines are not formed.

Evaluation of a Chemical Spot-Test Kit for the Detection of Airborne Particulate Lead in the Workplace

A commercial rhodizonate-based test kit was evaluated for its potential use in the detection of lead in airborne particulate samples at work sites. Over 350 air samples were collected at abrasive blasting lead paint abatement sites using cellulose ester membrane filters and personal sampling pumps. The filter samples were tested with the chemical spot test and then analyzed by graphite furnace atomic absorption spectrophotometry. No positive readings were recorded for lead masses below 1.3 µg Pb/filter, and no negative readings were observed for lead amounts above 8.1 µg Pb/filter. Experimental data were statistically modeled in an effort to estimate the performance parameters of the spot test kit. The identification limit of the kit was found to be approximately 3.6 µg/filter sample. For lead mass values above approximately 10 µg Pb/filter, 95% confidence of a positive reading was found; while 95% confidence of a negative reading was found for lead masses below approximately 0.6 µg Pb/filter. Based on the results of this study the rhodizonate-based test kit for lead demonstrates potential for use in field screening for lead in personal breathing zone and area air samples.

Evaluation of a chemical spot-test kit for the detection of airborne particulate lead in the workplace.

A commercial rhodizonate-based test kit was evaluated for its potential use in the detection of lead in airborne particulate samples at work sites. Over 350 air samples were collected at abrasive blasting lead paint abatement sites using cellulose ester membrane filters and personal sampling pumps. The filter samples were tested with the chemical spot test and then analyzed by graphite furnace atomic absorption spectrophotometry. No positive readings were recorded for lead masses below 1.3 micrograms Pb/filter, and no negative readings were observed for lead amounts above 8.1 micrograms Pb/filter. Experimental data were statistically molded in an effort to estimate the performance parameters of the spot test kit. The identification limit of the kit was found to be approximately 3.6 microgram/filter sample. For lead mass values above approximately 10 micrograms Pb/filter, 95% confidence of a positive reading was found, while 95% confidence of a negative reading was found for lead masses below approximately 0.6 micrograms Pb/filter. Based on the results of this study the rhodizonate-based test kit for lead demonstrates potential for use in field screening for lead in personal breathing zone and area air samples.

QUANTIFICATION OF OCCUPATIONAL LATEX AEROALLERGENS IN A MEDICAL CENTER

Measures to control exposure to latex can be monitored by area and personal air sampling with immunochemical approaches. Because of the increasing risk to health care professionals exposed to latex, the use of gloves with low allergen content or powder-free gloves appear to be most effective in reducing latex aeroallergen levels.

Measurements of Air Concentrations of Thorium During Grinding and Welding Operations Using Thoriated Tungsten Electrodes

An evaluation was performed to determine whether thorium was present in concentrations above the derived air concentration during grinding and welding operations using thoriated tungsten electrodes. A few of the advantages of using thoriated tungsten electrodes in industry include easier are starting, greater stability, and reduced weld metal contamination. The electrodes used in this evaluation contained 2% thoria (thorium oxide) and were either 2.4 mm or 3.9 mm in diameter. Personal breathing zone and area air samples were collected for the experienced welders participating in this evaluation during grinding operations. The results during the grinding operations for personal and area air samples were generally below the derived air concentration (DAC) for 232Th for solubility class Y of 0.04 Bq m-3 (1 x 10(-12) microCi mL-1) as per 10 CFR 20. The area samples collected during welding operations were below the DAC.

Detection of airborne natural rubber latex by immunoelectrophoresis, RAST inhibition, and immunospot method.

Occupational dermal and respiratory allergies caused by natural rubber latex (NRL) have been encountered with increasing frequency in health care workers. In order to measure the amount of airborne NRL, area and personal air sampling was performed in three hospital laboratories where workers used latex gloves. The total dust levels in laboratory air samples were lower than 0.17 mg/m3. RAST inhibition suggested that NRL antigens may exist both in the area and personal samples. Immunospot measurements, rocket immunoelectroporesis, and rocket radioimmunoelectrophoresis did not show any NRL activities in laboratory airsamples, although they were able to detect immunoactive material in positive control filter specimens. We conclude that the airborne NRL concentration was undetectable in daily hospital laboratory environment where workers used disposable NRL gloves. Airborne NRL, however, can be measured by using immunological assays.

Exposure Assessment and Respirator Selection in the Cleaning of Crude Oil Process Vessels

Abstract The processes in the oil production industry are generally closed systems. The workers who clean and maintain process vessels, however, are exposed to the hazards of crude oil and confined spaces. Although respiratory protection is often used by these workers, exposures have not been documented and respirator selection procedures using detector tubes to measure benzene concentrations have not been validated. This study evaluates the effectiveness of this approach to respirator selection by examining actual exposures of a group of vessel workers and assessing the adequacy of protection that was provided. Personal breathing zone samples and area samples were collected by active adsorptive sampling during the cleaning of oil separators. Area air samples were also collected prior to entry into the vessels in conjunction with detector tube sampling conducted by safety personnel. Adsorptive air sampling indicated that exposure concentrations ranged from nondetectable to 5.8 ppm, averaged over the durat...

Resuspension of Asbestos in Settled Dust in an Apartment Cleaning Situation

Abstract To gain information about the airborne asbestos levels to which an apartment dweller could be exposed as a C1 occupant, a simulation exercise was designed to study the upper limit of normal cleaning activity. Prior to the cleaning exercise, settled dust samples were collected to establish an index of asbestos fibers with potential for release from the surfaces in the apartment; microvac dust samples were collected from six locations where dust was to be disturbed. The cleaning exercise consisted of vacuuming the complete floor surface of the apartment continuously for 30 minutes using a commercial vacuum cleaner, followed by dry wiping of all appropriate surfaces for 30 minutes. During the cleaning, exercise area and personal air samples were collected. Before cleaning, asbestos in air measured less than 3 asbestos structures/L. During cleaning, air samples in the vicinity of the breathing zone of the person cleaning were below detection of phase contrast microscopy (PCM) (<0.04 f/ml) and 40–140 s/L by transmission electron microscopy. Dust samples showed levels of asbestos in the range of 2000–7000 str/cm2 except for one sample from the top of a gas heater. The index of asbestos in the settled dust, as determined by microvac test (weighted for surface area) was approximately 4000 str/cm2. Results showed a trace of asbestos was suspended into air at below the detection level of the PCM analysis. The resuspension factor “K” value was calculated to be in the range of 10−5 cm−1 using the average (personal) air sampling data and the average (area weighted) dust sampling data.

Quantification of occupational latex aeroallergens in a medical center

To determine the quantity, variability, and mean aerodynamic diameter of latex aeroallergens in a large medical center, we collected air samples from work sites by using area and personal breathing zone air samplers, and we measured latex allergens by an inhibition assay with IgE antibodies from latex-sensitive individuals. Latex aeroallergen concentrations in 11 areas where powdered latex gloves were frequently used ranged from 13 to 208 ng/m3, and in areas where powdered latex gloves were never or seldom used, concentrations ranged from 0.3 to 1.8 ng/m3. Installation and use of a laminar flow glove changing station in one work area did not reduce latex aeroallergen levels. Large quantities of allergen were recovered from used laboratory coats and anesthesia scrub suits and from laboratory surfaces. Latex allergen concentrations in personal breathing zone samplers worn by health care workers in areas where powdered gloves were frequently used ranged from 8 to 974 ng/m3. Exposure likely occurs when gloves are changed and as a result of resuspension from reservoirs of powder in the room and clothing. Latex allergens were found in all particle sizes but were predominant in particles greater than 7 μm in mass median aerodynamic diameter. Results of electrophoretic immunoblotting showed that the aeroallergens are primarily the higher molecular mass components of the latex glove proteins. Measures to control exposure can be monitored by both area and personal air sampling with this immunochemical approach. Use of gloves with low allergen content or powder-free gloves appears to be more effective than use of a laminar flow glove changing station in reducing aeroallergen levels. (J ALLERGY CLIN IMMUNOL 1994;94:445-51.)

EVALUATION AND CONTROL OF WORKER EXPOSURE TO FUNGI IN A BEET SUGAR REFINERY

A study of worker exposure to airborne fungi was undertaken in a sugar beet refinery to evaluate the level of exposure and to determine if controls could be implemented that would lower these exposures. A previous study at this refinery identified one worker who reacted on challenge testing to the moldy but not the fresh sugar beet pulp, had specific Immunoglobulin G to Aspergillus niger, and specific Immunoglobulin E to Aspergillus. Also, two employees were diagnosed with occupational asthma. In the study reported here, two field surveys were conducted, the first during the sugar production campaign (January) and the second during postproduction cleanup and maintenance (June). Approximately 65 personal and area air samples were collected on polycarbonate filters and the culturable fungal spores were identified and enumerated. This study showed high exposure of pellet loaders and pellet silo workers to various species of Aspergillus. Other fungal species that might pose a health hazard were detected. Exposures to fungi during the postproduction cleanup and maintenance phase were much higher than those measured during the production campaign. Engineering controls that would reduce employee exposure are discussed.