Workroom Air Research Articles

Toxicity and spectrophotometric determination of sulphur dioxide in air using a new absorbing agent

An aqueous solution of succinyldihydroxamic acid (SDHA) is proposed as an efficient absorbing agent for ambient sulphur dioxide. The agent (SDHA) is easy to prepare, has an absorption efficiency of approximately 100% and its resulting sulphite solution is stable for more than 30 d. The absorbed sulphur dioxide has been subsequently determined spectrophotometrically by condition optimised p-aminoazobenzene-formaldehyde in hydrochloric acid. The pink dye formed has an absorption maximum at 505 nm. The proposed method is superior to the widely used tetrachloromercurate method in terms of manipulation, speedy results and use of stable, pure and non-toxic reagents. The interference from nitrogen dioxide has been removed by the use of sodium azide-malonyl dihydrazide. The procedure has been applied to the determination of sulphur dioxide both in the vicinity of a superphosphate fertiliser plant and in work-room air.

Influence of air humidity on sampling efficiency of some solid adsorbents used for sampling organics from work-room air

The influence of air humidity on the sampling efficiency of Amberlite XAD porous polymers and activated charcoal was studied by determining the recovery of various organics at 20% and 85% relative humidity. The sampling efficiency of XAD-7 was found to decrease with increasing relative humidity, while the sampling efficiency of XAD-2 and activated charcoal was relatively unaffected for the compounds studied. Activated charcoal had a greater capacity than Amberlite XAD for several types of compounds, however.

Specificity of analytical methods used to determine the concentration of formaldehyde in workroom air

Interferences from 17 commonly occurring organic compounds to the determination of formaldehyde have been studied. The tested methods were acetylacetone (colorimetric and fluorometric) chromotropic acid (with and without evaporation), MBTH, pararosaniline and 2,4-dinitrophenylhydratzine-HPLC methods.

Sampling and analysis of hexavalent chromium during exposure to chromic acid mist and welding fumes.

Sampling and analysis of hexavalent chromium during exposure to chromic acid mist and welding fumes. Scand j work environ & health 9 (1983) 489-495. In view of the serious health effects of hexavalent chromium, the problems involved in its sampling and analysis in workroom air have been the subject of much concern. In this paper, the stability problems arising from the reduction of hexavalent to trivalent chromium during sampling, sample storage, and analysis are discussed. Replacement of sulfuric acid by a sodium acetate buffer (pH 4) as a leaching solution prior to analysis with the diphenylcarbazide (DPC) method is suggested and is demonstrated to be necessary in order to avoid reduction. Field samples were taken from two different industrial processes-manual metal arc welding on stainless steel without shield gas and chromium plating. A comparison was made of the DPC method, acidic dissolution with atomic absorption spectrophotometric (AAS) analysis, and the carbonate method. For chromic acid mist, the DPC method and AAS analysis were shown to give the same results. In the analysis of welding fumes, the modified DPC method gave the same results as the laborious and less sensitive carbonate method.

Determination of metaldehyde in workroom air.

Determination of metaldehyde in workroom air.

Toxicology of Sulphur Dioxide and its Spectrophotometric Determination in Air Using a New Absorbing Agent

Abstract An aqueous solution of malonyldihydroxamic acid is proposed for the absorption of atmospheric sulphur dioxide. The reagent has an absorption efficiency of ∼100% and the resulting sulfite solution is stable for more than 30 days. The effect of variables for absorption of sulphur dioxide such as reagent concentration, flow rate and temperature has been investigated. The absorbed sulphur dioxide has been subsequently determined spectrophotometrically by p-aminoazobenzene-formaldehyde reagent in hydrochloric acid medium at optimized conditions. The pink coloured dye has a γmax at 505 nm. The interference of nitrogen dioxide has been removed by use of sodium azide/oxalyldihydrazide. The proposed reagent is superior to TCM method in regard of manipulation, speedy results, use of stable and freely available pure and non-toxic reagents. The procedure has been applied for analysis of sulphur dioxide in vicinity of steel plant and work room air.

Changes in urinary delta-aminolevulinic acid at low lead exposure level with special reference to production activity.

A 7-year follow-up survey on 53 workers was carried out in a lead storage battery factory to evaluate the significance of urinary delta-aminolevulinic acid (ALA) and blood lead in a work environment where lead in the air was considered to be about or less than the current occupational exposure limit. While lead in the blood and ALA in the urine had a good correlation to each other cross-sectionally as well as longitudinally, geometric means of lead concentrations in the workroom air samples which were collected following grid sampling strategy, did not correlate with ALA in urine significantly. On the contrary, the semiannual production of batteries significantly correlated with changes in mean ALA in urine. The questionnaire survey proved that the prolongation in work hours, lead to an increase in the mean ALA in urine as well as a higher incidence of higher-than-normal urinary ALA. The results clearly demonstrated the importance of the biological indicators, such as lead in blood and urinary ALA, as well as the necessity of paying attention to non-industrial hygiene factors, such as the production rate of batteries and the length of the daily shift, for the protection of the workers' health when lead in the air is moderate.

Increased frequency of lymphocyte micronuclei in workers producing reinforced polyester resin with low exposure to styrene.

A new micronucleus method based on the analysis of lymphocytes with preserved cytoplasm revealed an increased frequency of micronuclei in 38 workers employed in a plant producing styrene-modified polyester resin as compared to the frequency in 20 referents (5.9 vs 3.6%). The time-weighted average of the styrene concentration in the workroom air varied between 1 and 36 ppm (mean 13 ppm) during the last year and correlated well to low urinary levels of mandelic acid, which ranged from 9 to 316 mg/g of creatinine (mean 65 mg/g of creatinine).

Evaluation of solid sorbents for sampling aliphatic and aromatic nitro compounds in work-room air

Amberlite XAD-2 and XAD-7 porous polymers were evaluated for the solid sampling of aliphatic and aromatic nitro compounds in work-room air. With the use of solvent desorption, XAD-2 gave 80–100% recovery of nitroaromatics, and XAD-7 85–100% recovery of nitroaliphatics. The compounds studied were nitromethane, nitroethane, 2-nitropropane, nitrobenzene, m -dinitrobenzene and 2,4,6-trinitrotoluene. All six compounds gave very poor recoveries from activated charcoal.

Evaluation of solid sorbents for sampling nitroglycerin, ethylene glycol dinitrate and isopropyl nitrate in work-room air

Activated charcoal, Amberlite XAD-2, and Amberlite XAD-7 have been evaluated for the solid sampling of airborne nitroglycerin, ethylene glycol dinitrate and isopropyl nitrate. With the use of diethyl ether for solvent desorption, XAD-2 was found superior for sampling nitroglycerin and ethylene glycol dinitrate. Both XAD-7 and activated charcoal gave high recoveries for isopropyl nitrate; charcoal had a greater capacity than XAD-7 for this compound, however.

Standards for chemical quality of drinking water: a critical assessment.

The author critically reviews present standards for the chemical quality of drinking water, particularly the limits proposed by the Commission of the European Communities (CEC) in 1979. Particularly, the general principles of standard setting are discussed. It appears that there exists a surprisingly high similarity in drinking water limits, issued by various national and international authorities, although for other environmental compartments important discrepancies exist. Usually, drinking water limits lack adequate documentation, and appear often to be copied from other existing lists. There is an apparent lack of logical consistency in limits set for food, ambient or workroom air, and drinking water, probably due to lack of communication between health experts and decision-making authorities. Moreover, there is a lack of toxicologic studies, explicitly aimed at setting limits. Extrapolation from the acceptable daily intakes (ADI) for food or the Threshold Limit Value (TLV)-Maximum Acceptable Concentration (MAC) for workroom air could be undertaken to derive tentative drinking water limits, as long as explicitly designed studies for drinking water are not yet available.

Sampling of ethylene glycol and ethylene glycol derivatives in work-room air using Amberlite XAD resins

The porous polymers Amberlite XAD-2 and XAD-7 were evaluated for the sampling of ethylene glycol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol and 2-ethoxyethyl acetate in work-room air. Using diethyl ether desorption, these adsorbents were found excellent for the compounds studied.

Occupational and in vitro exposure to styrene assessed by unscheduled DNA synthesis in resting human lymphocytes.

Lymphocytes from 38 individuals occupationally exposed to styrene concentrations in workroom air of 1 p.p.m. t0 40 p.p.m. were examined for any genotoxic effects using unscheduled DNA synthesis (UDS) as the indicator of DNA damage. The mean level of N-acetoxy-2-acetylaminofluorene (NA-AAF) induced UDS was significantly increases (p less than 0.001) for the styrene exposed group when compared to the mean level for the unexposed controls. There was no significant effect on u.v.-induced UDS from the in vivo styrene exposure. Lymphocyte cultures exposed in in vitro to styrene concentrations up to 100 micro M have confirmed the UDS data collected on individuals occupationally exposed to styrene. In addition, the in vitro study has also shown that the increased NA-AAF induced UDS resulting from styrene exposure was paralleled by a similar increase in NA-AAF binding to DNA. Taken together these results indicate that styrene exposure does not inhibit DNA repair synthesis, but rather it predisposes lymphocytes to an increased risk for DNA damage induction from subsequent genotoxic exposures.

Levels of methylmethacrylate, formaldehyde, and asbestos in dental workroom air.

The levels of methylmethacrylate and formaldehyde in workroom air of a dental laboratory following finishing and polishing a pour type denture base resin have been measured. The levels of these compounds did not exceed the respective hygienic threshold limit values in the general workroom air or in breathing air close to workpiece. The content of asbestos fibers in breathing air released during dismantling molds from gold casting was measured. During the dismantling procedure the fiber content in the air could exceed threshold limit values by up to about 12 times. However, about 10 min after terminating this process the fiber content had declined to a level below the establish requirements.

Occupational exposure to polychlorinated biphenyls in electrical workers. I. Environmental and blood polychlorinated biphenyls concentrations.

Industrial exposure to polychlorinated biphenyls (PCBs) and internal dose were investigated in 80 worker exposed for many years to PCB mixtures with a 42% chlorine content (Pyralene 3010 and Apirolio). PCBs were determined by liquid gas chromatography on samples taken from workroom air, workroom surfaces and tools, the palms of the hand, and the blood of the workers. In the workroom air samples, PCB concentrations ranged from 48 to 275 micrograms/m3. All tested surfaces and tools were heavily contaminated, with a range from 0.2 to 159 micrograms PCBs per cm2 of surface. Considerable amounts of PCBs were detected on the palms of the hands of the workers (2-28 microgram/cm2 of skin surface). In blood, total PCB concentrations from 88 to 1319 micrograms/kg were observed: comparing the blood concentrations of low and high chlorine content biphenyls, a significant difference was found for the low-chlorinated biphenyl concentrations between workers currently exposed and workers exposed only in the past. In groups of workers who were homogeneous as regards work area and job, the PCB concentrations in the blood were closely correlated with the length of actual occupational exposure to these compounds. These findings led to the conclusion that absorption of PCBs in these workers had occurred mainly through the skin, therefore industrial preventive surveillance must take this route of exposure into account. Since blood PCB concentrations appear to be correlated with the length of exposure, PCB determination on whole blood may be used to monitor industrial and environmental exposure to PCBs.

Sampling of polychlorinated aromatics in workroom air using Amberlite XAD-2 resin

Amberlite XAD-2 porous polymer was evaluated for the solid sampling of PCBs, PCNs, tri-, tetra-and pentachlorophenol in workroom air. Using solvent desorption, the recoveries of these compounds from XAD-2 was mostly about 80%, showing this adsorbent to be an excellent medium for the sampling of polychlorinated aromatics in air.

Sampling of epichlorohydrin and ethylene chlorohydrin in workroom air using Amberlite XAD-7 resin

Activated charcoal, Amberlite XAD-2 and Amberlite XAD-7 were evaluated for the adsorption of epichlorohydrin and ethylene chlorohydrin from air followed by desorption with solvent. Ethylene chlorohydrin was found to be unstable on activated charcoal in the presence of carbon disulfide. Recoveries from XAD-2 were low, and XAD-7 was found to be the best adsorbent for the sampling of these compounds from air.

Cytogenetic and cytokinetic investigations on lymphocytes from workers occupationally exposed to tetrachloroethylene

Lymphocytes from 10 factory workers, who had been exposed to tetrachloroethylene for 3 months to 18 years, were examined for possible chromosome aberration, increased sister chromatid exchanges, and modified cell-cycle kinetics. The exposure intensity was such that the workroom air analyses disclosed 92 ppm as a geometric mean in the workshops for Group 1 (6 workers from degreasing workshops), but was in the range of 10 to 40 ppm for Group 2 (4 workers from a support department). Urinalyses for total trichloro-compounds showed 50.7 and 19.0 mg (as trichloroacetic acid)/l as a geometric mean in Group 1 and 2, respectively. Cytogenetic and cytokinetic studies did not reveal any significant dose-related changes in chromosome aberrations (either numerical or structural), SCEs rate, the proportion of M 2 + M 3 metaphases or mitotic index, compared with concurrent controls. Mitomycin C treatment also failed to induce any difference between exposed workers and controls.

Analysis of methylisothiocyanate derived from the soil fumigant metham-sodium in workroom air.

Analysis of methylisothiocyanate derived from the soil fumigant metham-sodium in workroom air.

Increased frequency of chromosome aberrations in workers exposed to styrene.

Chromosomal aberrations in lymphocytes from peripheral blood were significantly more frequent in six workers from a plant manufacturing polyester resin boats (average 10.8 per 100 cells) than in six age-and sex-matched referents (5.2 per 100 cells). The contamination of the workroom air with styrene, as measured on three occasions within three years in different areas of the plant, was 50--400 mg/m3.