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Biomedical subjects

P C Holmberg

Publications and source records attributed to P C Holmberg.

At least 19 recordsLinked to original sources
PubMed1997

Sensitization to industrial enzymes in enzyme research and production.

OBJECTIVES: This study investigated sensitization to industrial enzymes in Finnish enzyme production and in Finnish laboratories. METHODS: A cross-sectional study was conducted in 2 plants producing industrial enzymes and in their product development and research laboratories. Sensitization to enzymes and environmental allergens was examined by skin prick tests and specific immunoglobulin E determinations (radioallergosorbent test). The employees were interviewed for work-related respiratory symptoms. Altogether 173 employees were examined. RESULTS: The skin prick test showed 21 employees (12%) to be sensitized to one or more enzymes. Sixteen positive persons also had specific immunoglobulin E. Atopy was distinctly associated with enzyme sensitization. An exposure-response relationship was found for enzyme sensitization and for respiratory symptoms during work. For sensitization, the exposure-response linear trend was statistically significant. It weakened but remained statistically significant after stratification for atopy. For symptoms, likewise, the exposure-response linear trend was statistically significant, and the statistical significance remained after stratification for atopy. CONCLUSION: The study confirmed that industrial enzymes are potent sensitizers. The handling of dry enzymes in laboratory work may cause sensitization. Sensitization may even follow minute degrees of exposure, such as among office personnel. Atopics are more susceptible to sensitization than nonatopics. Nonatopics are also clearly at risk; the demonstrated exposure-response relationship emphasizes the need for and advantages of proper exposure control.

Adult↗
PubMed1996

Enzyme exposure and enzyme sensitisation in the baking industry.

OBJECTIVES: To assess the exposure to enzymes and prevalence of enzyme sensitisation in the baking industry. METHODS: A cross sectional study was conducted in four bakeries, one flour mill, and one crispbread factory. Sensitisation to enzymes, flours, and storage mites was examined by skin prick and radioallergosorbent (RAST) tests. 365 workers were tested. The workers were interviewed for work related respiratory and skin symptoms. Total dust concentrations were measured by a gravimetric method, and the concentration of alpha-amylase in air was measured by a catalytic method. An immunochemical method was used for measuring cellulase and xylanase in air. RESULTS: Total measured dust concentrations were from 0.1 to 18 mg/m3, with highest values in dough making areas of bakeries. The alpha-amylase concentrations generally followed the total dust concentrations and reached the highest values < 6.6 micrograms/m3 in the same areas. Cellulase and xylanase varied with concentrations < 180 ng/m3 and < 40 ng/m3, respectively, in the flour mill and the crispbread factory. No cellulase, but concentrations of 1-200 ng/m3 xylanase, were found in the bakeries, probably indicating the natural xylanase activity of wheat. 12 workers (8%) in the bakeries, three (5%) in the flour mill, and four (3%) in the crispbread factory were skin prick positive to enzymes. The corresponding percentages of positive reactions to flours were 12%, 5%, and 8%. CONCLUSIONS: The study confirmed that industrial enzymes in baking used as additives in a powdered form pose a risk of sensitisation. The no effect air concentrations for industrial enzymes are not known. Based on present knowledge, however, lowering exposures and eliminating short and high peaks by technical measures would lower the risk of sensitisation. This would be most effectively accomplished by shifting to non-dusty products.

Adult↗
PubMed1995

Agricultural work during pregnancy and selected structural malformations in Finland.

We studied the relation between birth defects and maternal agricultural work in a nationwide time- and area-matched case-referent series of 1,306 pairs of infants (581 orofacial clefts, 365 central nervous system defects, 360 skeletal defects) obtained through the Finnish Register of Congenital Malformations. We supplemented the Register data, including the mothers' latest and previous pregnancies, diseases, consumption of drugs and alcohol, smoking habits, and the like, with detailed interviews on the mothers' work conditions. When all of the birth defects were pooled and agricultural work was compared with nonagricultural work in the first trimester of pregnancy, the adjusted odds ratio was 1.4 [95% confidence interval (CI) = 0.9-2.0]. For orofacial clefts, the corresponding odds ratio was 1.9 (95% CI = 1.1-3.5). An industrial hygienist's blinded assessment indicated that seven mothers of infants with orofacial clefts and three reference mothers had been exposed to pesticides in agricultural work; the adjusted odds ratio for work with pesticide exposure, when compared with unexposed agricultural work, was 1.9 (95% CI = 0.4-8.3). Exposure to solvents did not explain the observed association.

Abnormalities, Drug-Induced↗
PubMed1991

Anencephaly and maternal common cold.

To study the risk of anencephaly related to common cold during pregnancy, a case-control study was made. The series comprised 393 Finnish mothers of anencephalic children and their time-area-matched controls in the period 1964 through 1982. Seventy mothers of anencephalic infants and 17 controls had reported common cold in the first trimester [adjusted odds ratio 4.5; 95% confidence interval (2.2-9.1)]. Reported common cold in the second trimester was not associated with anencephaly. As suggested by our previous cohort study in the same population, a true viral influenza resembling "common cold" might not explain the observed association.

Anencephaly↗
PubMed1990

Influenza epidemics and anencephaly.

To explore the postulated association between maternal influenza and congenital defects of the central nervous system, 14 virologically verified epidemics in Finland, 1969-82, were studied. Mothers of 248 anencephalic children were grouped into those whose first trimester had occurred during an epidemic period and those whose pregnancy had commenced during a non-epidemic period. No significant differences in prevalence of anencephaly were noted in these groups.

Adult↗
PubMed1989

Noise exposure during pregnancy and selected structural malformations in infants.

The study tested the hypothesis of exposure to noise during pregnancy being teratogenic. It included 1,475 Finnish mothers who had given birth to a malformed child (orofacial cleft or structural defect of the central nervous system, skeleton, or heart and great vessels) and 1,475 reference mothers. A special interview soon after delivery yielded the primary information on exposure. Of the 783 mothers who reported noise exposure in the first trimester, 370 were case mothers and 413 were referents. Hygienic assessment indicated that 102 case mothers and 103 referents had been exposed in the first trimester to a sound level of around 80 dB LAeq(8 h) or higher, the overall odds ratio being 1.0 (95% confidence interval 0.7-1.3). Adjustment for potential confounders by logistic regression methods gave similar results. There was no obvious trend suggesting a hazard when different exposure categories were considered.

Congenital Abnormalities↗
PubMed1988

Cardiovascular malformations, work attendance, and occupational exposures during pregnancy in Finland.

To explore for associations between occupational factors and cardiovascular malformations, information on the parents of 160 infants with cardiovascular malformations and 160 control parents was studied. The case infants had been reported consecutively to the Finnish Register of Congenital Malformations. All mothers were interviewed identically after delivery, using both open and pro forma questions about detailed work tasks, exposures, and leisure activities during pregnancy. The interview information was evaluated blindly. Neither parental occupational titles nor maternal working per se gave new clues to the teratogenic risk; nor did shift working, wearing of personal protective equipment, or the mother's own opinion on exposures during pregnancy. Identified occupational exposures, as categorized by an industrial hygienist, showed no remarkable associations to cardiovascular malformations. Few mothers were exposed substantially to specific occupational hazards. Comparing mothers who used medications in the first trimester with those who did not showed an odds ratio of 2.2 (95% confidence interval 1.3-3.9) when adjusted for potential confounding by multivariate logistic methods.

Abnormalities, Drug-Induced↗
PubMed1985

Birth defects and exposure to video display terminals during pregnancy. A Finnish case-referent study.

In a test of the widely publicized allegation that exposure to video display terminals causes birth defects, interview forms of mothers of 1 475 children reported consecutively to the Finnish Register of Congenital Malformations to have defects of the central nervous system, orofacial clefts, skeletal defects, or cardiovascular malformations and the forms of the same number of their paired referents were studied. The scrutiny revealed 490 mothers with occupational titles indicating potential exposure to video display terminals. Of the 490, 235 were case mothers and 255 were referents. Then, unaware of the case-referent status, three members of the research team perused the mothers' interview descriptions of workday activities for information indicating exposure to video display terminals. Work with such terminals during the first trimester of pregnancy was ascertained for 111 mothers. Of these, 51 were case mothers and 60 were referents. The comparison of the mothers exposed to video display terminals during the first trimester with those not exposed at all showed a crude odds-ratio point estimate of 0.9 with 95% confidence limits of 0.6 and 1.2. Adjustment for potential confounders by multivariate logistic regression methods did not materially affect the risk estimates. The results did not indicate a teratogenic risk for operators of video display terminals.

Adult↗
PubMed1983

Coffee consumption during pregnancy and selected congenital malformations: a nationwide case-control study.

Finland leads the world in per capita coffee consumption. To evaluate the hypothesis that coffee consumption during pregnancy is teratogenic, 755 pairs of mothers of malformed children and their controls were personally interviewed soon after delivery. After excluding tea drinkers and pairs with inadequate information, the study group included 706 pairs. Study subjects consisted of mothers of children with 112 defects of the central nervous system, 241 orofacial clefts, 210 structural defects of the skeleton, and 143 cardiovascular malformations. The coffee consumption during pregnancy was similar for the mothers of malformed or non-malformed children. The comparison of the mothers drinking at least four cups of coffee a day during pregnancy with those not consuming coffee at all showed a relative risk point estimate of 1.0 with the 95 per cent confidence limits of 0.7 and 1.3.

Abnormalities, Drug-Induced↗
PubMed1983

Screening for occupational exposures and congenital malformations.

Since 1976 the Finnish matched-pair Register of Congenital Malformations has been linked to a special project which screens for associations between selected congenital malformations and chemical and physical exposures during early pregnancy. Case mothers and their referents are personally interviewed. Exposure data are quantitated blindly by a team of industrial hygienists and occupational health experts. An analysis of data from 1,047 pairs is now underway. The pairs consist of 289 defects of the central nervous system, 421 orofacial clefts, 200 selected structural malformations of the skeleton, and 137 selected cardiovascular defects. Exposure to organic solvents was associated with defects of the central nervous system in the initial two-year material. However this association was no longer detectable during the following three-year period. More pairs must be gathered before a reasonable judgment regarding the teratogenic potential of solvents becomes possible.

Abnormalities, Drug-Induced↗
PubMed1982

Sauna and congenital defects.

To test a recent hypothesis on the causal relationship between sauna-induced hyperthermia and congenital defects, 100 consecutive cases of defects of the central nervous system and 202 cases of orofacial clefts were singled out from the Finnish Registry of Malformations. The mothers and their time-area-matched referents were interviewed for their sauna habits. Almost every pregnant mother (98.5%) had visited the sauna regularly, and yet, the incidence of the CNS defects in Finland is among the lowest ever reported. No differences in the sauna habits were observed between the case and referent mothers. It is concluded that the relatively mild, temporal hyperthermia caused by the sauna should not be considered hazardous for the developing embryo.

Body Temperature↗
PubMed1982

Oral clefts and organic solvent exposure during pregnancy.

A cumulative case-referent study concerning selected exposures during pregnancy among mothers to children born with oral clefts has been in progress in Finland since December 1, 1977. The present study covering the initial 3.5 years' material can be regarded as a specific, more detailed extension of earlier retrospective studies concerning environmental factors in the causation of oral clefts, using material accumulated from the Finnish Register of Congenital Malformations. Information on exposures was gained by personal interviews with all the mothers. The analysis of different exposures and the classification of the material were performed blindly. Significantly more case-mothers than referent-mothers had been exposed to organic solvents during the first trimester of pregnancy (P less than 0.05).

Abnormalities, Drug-Induced↗
PubMed1982

Obstetric histories of women occupationally exposed to styrene.

To evaluate the possible embryotoxic effects of styrene, 67 female lamination workers occupationally exposed to styrene and 67 age-matched female industrial workers with no obvious chemical exposure were interviewed. The women, all under 40 a of age, did not differ significantly with respect to number of births, pregnancies, or spontaneous and induced abortions prior to the exposure period. During the styrene exposure the number of births was significantly lower among the exposed group, a result partly explained by a higher number of induced abortions. No differences were found in this material with regard to the number of spontaneous abortions.

Abnormalities, Drug-Induced↗
PubMed1981

Temporal characteristics related to leave from work and pregnancy among mothers with congenitally malformed offspring.

The possible impact of occupational factors on the furtherance of congenital defects have been under study at our department for the past 4 years. The topic has assumed a special interest because of the importance of the issue involved, namely the search for a possibility to prevent teratogenesis, and partly because the applicable methods are different from those of "customary" epidemiology. In connection with a register-based, case-referent study utilizing supplementary information, acquired via questioning, of conditions at the mothers' work places, we analysed various time-related events in their pregnancy. We found that the groups compared differed from each other with regard to the correct timing of the birth, despite the fact that the distribution of the times of stopping work for various reasons were alike. Among mothers who were granted sick leave from work the diagnosis of anencephaly became less common close to the estimated date of delivery, and conversely for the diagnosis of hydrocephaly. The findings of the present study may suggest that the time of assignment for a statutory maternity leave be considered. Methodological issues in study design are also briefly discussed.

Congenital Abnormalities↗