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T Kauppinen

Publications and source records attributed to T Kauppinen.

66 records · Page 4Linked to original sources
PubMed1990

Formaldehyde exposure and respiratory cancer among woodworkers--an update.

Respiratory cancer was examined in relation to occupational formaldehyde exposure in a case-referent study (136 cases, 408 referents) nested in a woodworker cohort. Plant- and time-specific job-exposure matrices were constructed for formaldehyde exposure. Over 3 ppm-months of formaldehyde exposure was associated with an odds ratio of 1.4 [90% confidence interval (90% CI) 0.5-4.1]. The odds ratios for lung cancer were near unity, the excess risk concentrating on the upper respiratory tract. That for combined exposure to formaldehyde-phenol exposure (all respiratory cancers) was 1.6 (90% CI 0.6-4.4) but 1.0 for formaldehyde only. No consistent exposure-response patterns emerged for the level, duration, or cumulative exposure. The results are hardly more than debatable support for the hypothesis concerning formaldehyde as a carcinogen in humans, the possible risk seemingly concentrating on the upper respiratory tract rather than the lung.

Case-Control Studies↗
PubMed1990

Complex chlorinated hydrocarbons: occupational exposure in the sawmill industry.

Exposure to chlorophenols occurs in the vicinity of the lumber treatment area in sawmills and in subsequent work phases where treated lumber is handled. Measurements from several countries indicate that the concentration of chlorophenols in the workroom air is generally below 0.5 mg/m3, the occupational exposure limit of chlorophenols in many countries. Inhalation usually leads to relatively low concentrations of chlorophenols in urine of exposed workers. Frequent skin contact with chlorophenol solution or with freshly treated lumber can produce urine concentrations 10-100 times higher than among those with inhalatory exposure only. In addition to chlorophenols, exposure to toxic polychlorinated dibenzodioxins and dibenzofurans may occur in some tasks carried out in sawmills. Jobs with potentially heavy exposure include the treatment of dipping-vat sludge and processes involving heating of chlorophenols, such as burning of treated waste wood and welding of metal structures contaminated by chlorophenols.

Hydrocarbons, Chlorinated↗
PubMed1988

Use of exposure registration in the prevention of occupational cancer in Finland.

A nationwide system for monitoring occupational exposure to a wide range of carcinogens has been in operation in Finland since 1979. The primary aim of the system is to lead to the identification, evaluation, and eventual elimination of the exposures. The number of exposed workers reported to the register was about 20,000 out of the work force of 2.3 million in 1979-1984. The most common exposures were chromates, nickel and its inorganic compounds, and asbestos. Data are presented to show that the system has been at least partially successful in decreasing exposures at work places. As an example, we discuss the decrease in the use of hydrazine, which was previously widely used as an anticorrosive agent at power plants. The statistical quality of the system is discussed, and possibilities for future research uses of the computerized data base are outlined.

Carcinogens↗
PubMed1988

Increased risk for primary liver cancer among women exposed to solvents.

An earlier case-referent study by the same authors [Int Arch Occup Environ Health 54 (1984) 147-153] reported that solvent-exposed women, but not men, had an increased risk for primary liver cancer. The present study was undertaken to verify these results. The relatives of deceased patients, ie, 377 liver cancer cases, 385 coronary infarction referents, and 476 stomach cancer referents, responded to a questionnaire on past employment and potentially relevant covariables, the response rates being 71.7, 72.7, and 69.0%, respectively. The information was assessed for solvent exposure by two occupational hygienists without knowledge of the patients' diagnoses. Seven male and seven female liver cancer cases had been exposed to solvents, the odds ratio being less than 1 for the men but greater than 3 for the women irrespective of the reference group used for comparison. The results confirm the authors' earlier findings. When both materials were combined, the odds ratio was 7.8 for the female liver cancer cases as compared with the infarction referents. In the combined material, nine female liver cancer cases, two stomach cancer referents, but no infarction referent had had at least probable exposure to chlorinated hydrocarbons. Such exposure was rare among all of the men in the study. This finding may explain why the increased liver cancer risk occurred only for the women, although a sex difference in sensitivity cannot be completely ruled out.

Adult↗
PubMed1988

Use of plant- and period-specific job-exposure matrices in studies on occupational cancer.

Job-exposure matrices were constructed and applied in the estimation of past exposures in a case-referent study nested within a cohort of Finnish woodworkers. The objective was to avoid bias in the risk estimates because of a misclassification of exposures. The matrices were constructed separately for each plant under study and each calendar year of follow-up. The level of exposure was incorporated in the matrices, since rather comprehensive data on exposures were available. The individual work histories were converted to exposure histories by a computer program which calculated several exposure indicators (eg, level and dose, with and without allowance for a latency period). The comparison between several indicators was thought to provide additional information for the final evaluation of results. The use of the plant- and period-specific job exposure matrices may be considered in cohort and nested case-referent studies on occupational hazards as an alternative to other procedures used in the estimation of exposures. Specific matrices may find broader applicability along with the increasing availability of detailed hygienic data.

Adult↗
PubMed1987

Exposure to asbestos during brake maintenance of automotive vehicles by different methods.

Asbestos concentrations were measured during the different operations of brake maintenance of passenger cars, trucks and buses in 24 Finnish workplaces. The estimated average asbestos exposure during the workday (8-hr time-weighted average) was 0.1-0.2 fibers/cm3 during brake repair of trucks or buses, and under 0.05 f/cm3 during repair of passenger car brakes when the background concentration was not included in the calculations. The background concentration was estimated to be less than 0.1 f/cm3. During brake maintenance of buses and trucks, heavy exposure, 0.3-125 (mean 56) f/cm3, was observed during machine grinding of new brake linings if local exhaust was not in use. Other short-term operations during which the concentration exceeded 1 f/cm3 were the cleaning of brakes with a brush, wet cloth or compressed air jet. During brake servicing of passenger cars, the concentration of asbestos exceeded 1 f/cm3 only during compressed air blowing without local exhaust. The different methods of decreasing the exposure and the risk of asbestos-related diseases among car mechanics are discussed.

Asbestos↗
PubMed1985

Chlorophenol exposure in sawmills.

Personnel exposures to chlorophenols were measured in ten Finnish sawmills where a chlorophenolate salt formulation was used for the blue stain control of sawed wood. The concentrations of chlorophenols in the air were usually well below the occupational limit value of 0.5 mg/m3. However, high concentrations (above 10 mg/m3) were measured inside heated kilns. Additionally, high concentrations were detected in the urine of workers whose skin came into contact with chlorophenol solution, indicating that chlorophenols are rapidly absorbed through the skin. The concentrations of chlorophenols in the air were low in trimming-grading plants where treated boards are handled, but some of the chlorophenols was bound to wood dust which is deposited mainly in the nose. The risks associated with the impurities contained in chlorophenol preparations (chlorinated dibenzodioxins and dibenzofurans) and the need for epidemiologic studies on possible cancer risks in sawmill work are discussed.

Air Pollutants, Occupational↗
PubMed1985

Salivary Streptococcus mutans count and gingivitis in children after rinsing with a chlorhexidine-fluoride solution with and without strontium.

Thirty schoolchildren, 9-12 yr old with high DMF score, rinsed their mouths twice a day for 3 days with a chlorhexidine-fluoride (CXF) solution or a chlorhexidine-fluoride-strontium (CXFSr) solution. Streptococcus mutans counts (CFU) were made from saliva incubated on MSB agar and the gingival bleeding was recorded both before and after the rinsing period. S. mutans count decreased significantly immediately after the rinsing with each of the solutions (from 650 X 10(3) to 170 X 10(3) CFU/ml by CXF and from 500 to 170 X 10(3) CFU/ml by CXFSr). Within about 18 days after the rinsing with each solution the salivary S. mutans counts returned to the original level. Gingival Bleeding Index (GBI) was significantly reduced by half through the CXF rinsing while the slight reduction by CXFSr was nonsignificant. Both of these changes were temporary. The results suggest that short rinsing periods with the CXF solution may be more advisable than daily rinses as a contribution to the maintenance of oral health in subjects or groups in need of such a prophylaxis. The weaker effect found with the CXFSr solution suggests that the cariostatic effect recently found in rats with the same solution may be due to other mechanisms than reduction of the oral S. mutans count.

Child↗
PubMed1985

Formaldehyde exposure and respiratory and related cancers. A case-referent study among Finnish woodworkers.

A case-referent study was undertaken to investigate the associations between formaldehyde exposure and respiratory and related cancers. Fifty-seven such cancers from a retrospective cohort of male woodworkers formed the case group. They were matched by year of birth with 171 referents. Exposure to formaldehyde was assessed with job-exposure matrices. The median of the time-weighted average concentration was about 1 ppm, and the mean duration of exposure was 10 years among the exposed. Odds ratios (OR) were calculated for formaldehyde exposure (1.44), peak exposure to formaldehyde (1.26), and exposure to formaldehyde-containing wood dust (1.22). None of the values exceeded unity with statistical significance. Allowance was also made for a 10-year period from the onset of exposure. Birth year, cigarette smoking and exposure to wood dust, chlorophenols, pesticides, and terpenes were controlled by stratification. The adjusted ORs did not change appreciably. The highest OR was 1.95 for formaldehyde exposure without allowance for minimum latency, adjusted for exposure to terpenes. No exposure-response relation was observed for the level, duration, or dose (ppm-years) of formaldehyde exposure. The result is nonpositive and may be explained by absence of effect, by too short a follow-up, or by insufficient power for detecting a mild excess risk.

Adult↗
PubMedDate not supplied

Iterative reconstruction algorithms in nuclear medicine.

Iterative reconstruction algorithms produce accurate images without streak artifacts as in filtered backprojection. They allow improved incorporation of important corrections for image degrading effects, such as attenuation, scatter and depth-dependent resolution. Only some corrections, which are important for accurate reconstruction in positron emission tomography and single photon emission computed tomography, can be applied to the data before filtered backprojection. The main limitation for introducing iterative algorithms in nuclear medicine has been computation time, which is much longer for iterative techniques than for filtered backprojection. Modern algorithms make use of acceleration techniques to speed up the reconstruction. These acceleration techniques and the development in computer processors have introduced iterative reconstruction in daily nuclear medicine routine. We give an overview of the most important iterative techniques and discuss the different corrections that can be incorporated to improve the image quality.

Algorithms↗
PubMedDate not supplied

Occupational exposure to chemical and biological agents in the nonproduction departments of pulp, paper, and paper product mills: an international study.

As part of an international epidemiological study of workers in the pulp and paper industry, previously unpublished exposure measurements were assembled in a database. This article describes 7293 measurements in nonproduction departments from 147 mills in 11 countries. The greatest variety of agents was measured in the maintenance, construction, and cleaning department, where high exposures to asbestos, chromium [VI] compounds, copper, mercury in urine, nitrogen dioxide, ozone, styrene, sulfur dioxide, trichloroethylene, and welding fumes were observed. Measurements in the storage, yard, loading, and shipping department indicated high exposures to asbestos, carbon monoxide, fungal spores, nitrogen oxides, sulfur dioxide, and total dust. The steam and power generation department had high exposures to methyl mercaptan, silica, and total dust. Measurements in process and effluent water treatment, laboratory and research, engineering, and office, administration, and cafeteria areas had few elevated exposures. Throughout the nonproduction departments, measurements of pulp-production chemicals such as chlorine and sulfur compounds tended to be low, with many below detection limits. There were some problems with the available data; in particular, detection limits were often not specified, and the data tended to be clustered in such a way that sources of exposure variability could not be distinguished. Despite these problems, the data provide new insight into the exposures of nonproduction pulp and paper industry personnel.

Databases, Factual↗