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Biomedical subjects

A Seldén

Publications and source records attributed to A Seldén.

15 recordsLinked to original sources
PubMed1999

Blood lead in Swedish police officers.

BACKGROUND: Shooting with lead-containing ammunition in firing ranges is a well-known source of lead exposure in adults, and police officers may be at risk of lead intoxication. More stringent national lead regulations stimulated a survey of blood lead (PbB) in Swedish police officers with regular shooting habits. METHODS: Police officers considered as the most active shooters on and/or off duty responded to a questionnaire about health, lifestyle, shooting habits, and potential lead exposure. Blood samples were collected and analyzed for PbB and a multivariate regression analysis was performed. RESULTS: The mean PbB in male officers (n = 75) was 0.24 mumol/L (5.0 micrograms/dL); range 0.05-0.88 mumol/L (1.0-18.2 micrograms/dL), and in female officers (n = 3) it was even lower (0.18 mumol/L; 3.7 micrograms/dL). For both sexes combined, a positive correlation (r = 0.55; P < 0.001) of PbB with the number of bullets annually fired both on and off duty was observed, and this finding remained in a multiple regression analysis including age, smoking habits, and latency from last shooting exercise. DISCUSSION: In conclusion, occupational and recreational lead exposure from firing ranges still seems to be a source of lead exposure in Swedish police officers, but it no longer appears to be a health risk. Lead-free communication and well-ventilated indoor firing ranges may have been decisive for this encouraging finding.

Adult↗
PubMed1997

Impact of nocturnal bruxism on mercury uptake from dental amalgams.

The mercury (Hg) release from dental amalgam fillings increases by mechanical stimulation. The aim of this study was to investigate the possible impact of nocturnal bruxism on Hg exposure from dental amalgams and to evaluate the effect of an occlusal appliance. 88 female patients from an orofacial pain clinic with a complete maxillary and mandibular dentition, a normal frontal vertical overbite with cuspid guidance, and at least 4 occlusal amalgam fillings in contact with antagonists in intercuspidal position, were examined with the Bruxcore bruxism monitoring device to measure the level of on-going nocturnal bruxism. Based on the degree of abrasion recorded, the subjects were divided into a group defined as bruxists, (n = 29), another group defined as non-bruxists, (n = 32), serving as controls, the intermediate group being discarded. The Hg exposure was assessed from the Hg concentration in plasma and urine, corrected for the creatinine content. In a regression model with bruxism as the only explanatory variable, no significant effect of bruxism was found, but when the number of amalgam fillings, chewing gum use, and other background variables were taken into account, there was a limited impact of bruxism on Hg in plasma. The nocturnal use of an occlusal appliance did not, however, significantly change the Hg levels. This study indicates that mechanical wear on amalgams from nocturnal bruxism may increase the Hg uptake, but the magnitude of this effect seems to be less than from the use of chewing gum.

Absorption↗
PubMed1996

Variability in the quantification of abrasion on the Bruxcore device.

The rate of abrasion of dental surfaces during short periods of time is difficult to measure clinically, but one quantifiable method is the use of the Bruxcore bruxism monitoring device. The aim of this study was to estimate the interobserver and intraobserver variation in the Bruxcore system using different reading methods. Fifteen volunteers used individually fabricated Bruxcore devices during 4 consecutive nights, and this procedure was repeated after 6 weeks. The abraded areas of the 30 Bruxcore devices were measured by two observers on two occasions and with three methods: microscope without a reference scale; microscope with a reference scale; and a computer-aided system. Intraobserver variation was small (5%), but interobserver variation was statistically significant for all three methods. The computer-aided system was superior to the other two methods. The interaction between Bruxcore values and observers was statistically significant for the microscope methods but not for the computer method. This was a desired property, indicating stability of the computer-aided method over the range of Bruxcore values observed. Small measurement errors, independent of the size of the measurements, can be expected using a trained observer and a computer-aided method for reading the Bruxcore bruxism monitoring device.

Adult↗
PubMed1994

Updated and expanded Swedish cohort study on trichloroethylene and cancer risk.

There is limited evidence for mutagenicity and carcinogenicity of trichloroethylene (TRI) in experimental test systems. Whether TRI is a human carcinogen is unclear, however. This paper presents an update and extension of a previously reported cohort of workers exposed to TRI, in total 1670 persons. Among men (n = 1421), the overall standardized mortality ratio (SMR) and cancer morbidity ratio (SIR) were close to the expected, with SMR, 0.97; 95% confidence interval (CI), 0.86 to 1.10; and SIR, 0.96; 95% CI, 0.80 to 1.16, respectively. The cancer mortality was significantly lower than expected (SMR, 0.65; 95% CI, 0.47 to 0.89), whereas an increased mortality from circulatory disorders (cardiovascular, cerebrovascular) was of borderline significance (SMR, 1.17; 95% CI, 1.00 to 1.37). No significant increase of cancer of any specific site was observed, except for a doubled incidence of nonmelanocytic skin cancer without correlation with the exposure categories. In the small female subcohort (n = 249), a nonsignificant increase of cancer and circulatory deaths was observed (SMR, 1.53 and 2.02, respectively). For both genders, however, excess risks were largely confined to groups of workers with lower exposure levels or short duration of exposure or both. It is concluded that this study provides no evidence that TRI is a human carcinogen, ie, when the exposure is as low as for this study population.

Adult↗
PubMed1993

Biological monitoring of hexachloroethane.

A small group (n = 12) of military white smoke munition workers provided blood plasma during a production break (S I) and after five weeks' production (S II) of a hexachloroethane (HCE)/titanium dioxide formula. Plasma was also obtained from a sex and age matched control group (n = 12) and a group (n = 13) of previously HCE-exposed workers, respectively. HCE in plasma (P-HCE) was determined with gas chromatography and electron capture detection. No HCE was found in the plasma samples from the two control groups. In the HCE exposed group the mean (+/- SD) P-HCE level increased almost two orders of magnitude from S I (0.08 +/- 0.14 microgram/l) to S II (7.30 +/- 6.04 micrograms/l) despite efforts to minimize the internal dose. Biological monitoring of HCE could be useful in occupational hygiene.

Adult↗
PubMed1993

Trichloroethylene exposure in vapour degreasing and the urinary excretion of N-acetyl-beta-D-glucosaminidase.

In order to elucidate the potential nephrotoxicity of low level occupational exposure to trichloroethylene (TRI), urine analysis of the tubular enzyme N-acetyl-beta-D-glucosaminidase (U-NAG) was included in a cross-sectional study of metal degreasers in central Sweden. Eighty-six percent of 8-h TRI in air measurements were well below 50 mg/m3. Normal levels of NAG were found in morning urine samples from 29 workers compared to a historical reference group. A weak positive correlation (r = 0.48; P < 0.01) was observed between U-NAG activity and the concentration of the TRI metabolite trichloroacetic acid in urine but not with other estimates of recent or long-term exposure. In conclusion, TRI does not seem to be nephrotoxic at low exposure levels.

Acetylglucosaminidase↗
PubMed1992

Methylene dianiline: assessment of exposure and cancer morbidity in power generator workers.

The biaromatic amine 4,4'-methylene dianiline (MDA) is an animal carcinogen, possibly also carcinogenic to humans. In a cohort of 595 power generator workers potentially exposed to MDA in a curing agent of an epoxy system, the overall standardised cancer incidence ratio (SIR) among males (n = 550), however, was only 0.52 [95% confidence interval (CI) 0.16-1.21] based on five observed cases. One male urinary bladder cancer case was found in comparison to 0.6 expected (SIR 1.67; 95% CI 0.04-9.31). This case was identified in an unexposed subcohort. High levels of MDA metabolites were ascertained in the urine of currently exposed workers, probably following percutaneous absorption. Although no evidence of an increased overall or bladder cancer risk was detected, the limitations of the study in regard to the size of the cohort, age and cancer latency preclude a definite risk assessment. The dermal absorption of MDA has been highlighted.

Aniline Compounds↗
PubMed1992

Assessment of intermittent trichloroethylene exposure in vapor degreasing.

To validate various sampling strategies in assessment of trichloroethylene (TCE) exposure, urine and air samples were obtained from 29 metal workers involved in vapor degreasing. Urinary trichloroacetic acid and trichloroethanol were useful metabolites to estimate TCE exposure on a group basis, but the predictive value of a single urine sample was low when related to the air concentration. With intermittent TCE exposure, the best information is obtained by analyzing both metabolites.

Adult↗
PubMed1991

Mortality and cancer morbidity after exposure to military aircraft fuel.

In order to elucidate a possible excess risk of lymphatic malignancies due to aircraft fuel exposure in the Swedish Armed Forces (SAF), a historical prospective cohort study was conducted. During a 9-year follow-up period, 3 cases of malignant lymphoma were detected versus 3.21 expected tumors of the lymphatic system (standardized incidence ratio (SIR) 93; 95% confidence interval (CI) 19-273) among 2,176 men. The overall SIR was 91 (CI 66-120), whereas the corresponding mortality ratio was only 54 (CI 42-68; p less than 0.001). In conclusion, no evidence was found for an association between military aircraft fuel and the occurrence of malignant lymphomas or other malignancies among exposed men in the SAF. For a definite risk assessment, further follow-up is necessary.

Adult↗