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Biomedical subjects

C A Nilsson

Publications and source records attributed to C A Nilsson.

At least 37 records · Page 2Linked to original sources
PubMed1987

Occupational exposure to chain saw exhausts in logging operations.

The composition of exhaust emissions from two-stroke chain saw engines was studied. The emissions of exhaust were sampled and analyzed under controlled laboratory experiments. The compounds sampled were those considered primarily responsible for acute health effects--hydrocarbons, aldehydes, nitrogen oxides and carbon monoxide. Exposure to tetramethyllead, dibromoethane and polycyclic aromatic hydrocarbons also was monitored. The results revealed no significant differences in the exhaust emissions from seven different chain saws. Heavily worn-out chain saws do not emit increased amounts of exhaust. A lean fuel-air mixture increases the emission of aldehydes and nitrogen oxides, whereas a rich mixture increases emission of carbon monoxide and hydrocarbons. Based on these new data on the composition of two-stroke chain saw exhaust emissions, operator exposure to chain saw exhaust was evaluated under various logging situations. Exposure measurements revealed no difference in average levels of exposure between logging in the presence or in the absence of snow. The felling operation, however, results in high exposure levels of short duration--especially when the operation is performed while there is deep snow on the ground. (This operation excludes limbing and bucking into lengths.) This is judged to be the main cause of the discomfort experienced by loggers. Average exposure levels for loggers engaged only in felling are twice those for cutters who also perform limbing, bucking and manual skidding of the timber, since these latter operations involve considerably lower exposure. Typical average levels of exposure are as follows: hydrocarbons, 20 mg/m3; benzene, 0.6 mg/m3; formaldehyde, 0.1 mg/m3; and carbon monoxide, 20 mg/m3.

Air Pollutants, Occupational↗
PubMed1985

Irritative complaints, carboxyhemoglobin increase and minor ventilatory function changes due to exposure to chain-saw exhaust.

Complaints of irritation in the eyes, nose and throat as well as dyspnea during work prompted this study to determine whether chain-saw exhaust produces acute exposure effects in loggers. Interviews concerning respiratory symptoms and rating of complaints were conducted for 211 loggers at industrial health care centers. Measurements of carboxyhemoglobin, spirometry and exposure to hydrocarbons, carbon monoxide and aldehydes were assessed for 23 loggers over 36 work periods lasting 2 h each. The prevalence of chronic bronchitis among the 211 loggers was 6%. Irritative complaints of eyes, nose and throat were common and significantly higher than in a reference group. The exposure levels were all below established threshold limit levels, except for carbon monoxide. There was a significant correlation between carbon monoxide exposure and blood carboxyhemoglobin levels. A small but significant decrease of FEV1% and FEF 25-75% during the work periods indicated minimal broncho-constriction, possibly mediated through a reflex mechanism due to irritation of upper airways.

Adolescent↗
PubMed1984

A new method for the analysis of tetramethyllead in blood.

In this paper a method for the determination of alkyllead compounds in blood is described. The method is based on extraction of the aklyllead compounds into an organic solvent, followed by separation by high-resolution gas chromatography. A graphite-furnace atomic absorption spectrophotometer is used as the detector. A detection limit of 0.01 micrograms/ml for tetramethyllead was obtained in blood samples. The method was used for the investigation of occupational exposure to tetramethyllead in gasoline. Blood samples from tank cleaners and gasoline pump servicemen showed detectable amounts of tetramethyllead. The reference group did not show any detectable levels of tetramethyllead.

Chromatography, Gas↗
PubMed1983

Monitoring 1,6-hexamethylene diisocyanate in air by chemosorption sampling.

Monitoring 1,6-hexamethylene diisocyanate in air by chemosorption sampling. Scand j work environ health 9 (1983) 497-503. A sampling procedure for 1,6-hexamethylene diisocynate (HDI) in air is described. The diisocyanate is trapped on a chemosorption tube containing 9-(N-methylaminomethyl)anthracene adsorbed on Amberlite XAD-2. Recoveries in the laboratory experiments were 81-91%. The chemosorption technique was evaluated in the field by measurements at two different factories using HDI as a hardener in two-component paints for vehicle refinishing. Simultaneous sampling with a fritted-glass bubbler and by the chemosorption technique showed equal collection efficiencies for HDI when 3.5- to 22-1 air samples were used. For air samples exceeding 20 1 the collection efficiency of the fritted-glass bubbler decreased. Several additional peaks appeared in the chromatograms from the fritted-glass bubblers. Statistical treatment of the data showed that these peaks are closely related to the amount of HDI.

Air Pollutants, Occupational↗
PubMed1983

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.

Air Pollutants, Occupational↗
PubMed1981

Chemosorption sampling and analysis of formaldehyde in air. Influence on recovery during the simultaneous sampling of formaldehyde, phenol, furfural and furfuryl alcohol.

A method based on trapping formaldehyde on a 2,4-dinitrodinitrophenylhydrazine-coated porous polymer (Amberlite XAD-2) was evaluated for air sampling in occupational environments. The aldehyde is converted to its 2,4-dinitrophenylhydrazone on the adsorbent. The influence of some organic compounds which often occur together with formaldehyde-furfural, phenol and furfuryl alcohol--was studied. The results show that the method allows the sampling of formaldehyde in the range 0.01--1.0 mg/m3 of air, based on a 3-1 (15 min) sample and a coating of 1%. Furfural, phenol, and furfuryl alcohol do not interfere and may be conveniently sampled at the same time. Formaldehyde and furfural hydrazones were analyzed by high-performance liquid chromatography, phenol and furfuryl alcohol by gas chromatography.

Air Pollution↗
PubMed1980

Negative ion mass spectra of some polychlorinated 2-phenoxyphenols.

Polychlorinated 2-phenoxyphenols were studied by negative ion mass spectrometry. Common to almost all of the methane enhanced negative ion mass spectra were (M-1)-, (M-36-)-., (M-37)-, (M-72)-., and chorinated quinoxide ions. The (M-36)-. ion does not apparently form in a mechanism analogous to the thermal or photochemical ring closure of these compounds to form the chlorinated dioxins. The chlorinated quinoxide ion reflects the number of chlorines on the ring with hydroxy substituent. Collision-induced dissociation mass-analyzed ion kinetic energy spectra (CID-MIKES) from different isomers were qualitatively different in both the normal and charge reversed mode of operation. Comparison of these spectra with those from other classes of polychlorinated aromatic hydrocarbons such as the dioxins or the furans may reveal a common negative ion gas phase chemistry.

Anions↗
PubMed1979

Methane-oxygen enhanced negative ion mass spectra of polychlorinated diphenyl ethers.

Methane-oxygen enhanced negative ion mass spectra of 15 chlorinated diphenyl ethers contained some combination of [M-]-., [M-1]-, [M-19]-, [M-36]-, [M-55]-, and [M+35]- anions. The relative abundances of these ions are related to the chlorine substitution pattern. Similar ions appear in the negative ion spectra of polychlorinated anisoles. The study of known isomers of polychlorinated model compounds extends the utility of the negative ion method in the analysis of polychlorinated aromatics such as polychlorinated biphenyls, dioxins and furans. The spectra were shown to be very dependent on the temperature of the ion source; a temperature change of 25 degrees C was shown to have pronounced effects. Spectral variation with temperature has implications for computer library searches, ultimate sensitivity limits and analysis in the presence of interfering isobaric ions.

Chlorobenzenes↗
PubMed1976

Use of chlorophenols as fungicides in sawmills.

Several commercial formulations of chlorophenols used as fungicides in sawmills were found to contain impurities, some of which are known to be much more toxic than the main products. The most frequent impurities were chlorinated phenoxyphenols, chlorinated diphenyl ethers, chlorinated dibenzofurans, and chlorinated dibenzodioxins. Samples of wood dust from several positions in two Swedish sawmills were analyzed. The results suggest that the impurities in the chlorophenol formulations are enriched in the work environment in relation to the chlorophenols themselves, probably because of the low volatility and high chemical stability of the impurities. The effect of various methods of fungicide application on the work environment is discussed.

Fungicides, Industrial↗