Ulla Björs

Bio: Ulla Björs is an academic researcher from Karolinska Institutet. The author has contributed to research in topics: Pregnancy & Cord blood. The author has an hindex of 2, co-authored 4 publications receiving 240 citations.

Quality control samples for the determination of lead and cadmium in blood, feces, air filters, and dust

Abstract: Quality control samples for the determination of lead and cadmium in blood, feces, air filters, and dust have been prepared within the UNEP/WHO Human Exposure Assessment Location (HEAL) Project. The preparation is given in detail. Problems related to sample preparation and reference values are discussed.

Undersökning av kvicksilverexponering hos gravida kvinnor i Uppsala län

Abstract: Den övergripande målsättningen med den hälsorelaterade miljöövervakningen (HÄMI) är att övervaka halter av miljöföroreningar över tid, speciellt hos känsliga och riskutsatta grupper, och att försöka identifiera de huvudsakliga exponeringskällorna för att uppnå en effektiv exponeringsreducering. Det specifika syftet med föreliggande projekt var att bestämma exponeringen för kvicksilver, framförallt metylkvicksilver (MeHg), hos gravida kvinnor som utgör en riskgrupp i den allmänna befolkningen eftersom fostret är speciellt känsligt för MeHg. Resultaten från studien skall jämföras med resultat från tidigare projekt inom HÄMI för att ge bättre underlag för riskbedömning av kvicksilverexponering hos kvinnor, foster och barn, samt identifiera vilka preventiva åtgärder som har störst effekt på exponeringen. Föreliggande undersökning har utförts i samarbete mellan Institutet för Miljömedicin (IMM), Karolinska Institutet och Livsmedelsverket på uppdrag av Naturvårdsverket.

Metaller i miljön - riskfaktorer under graviditet och amning

Abstract: When investigating metal concentrations during pregnancy, it is important to consider thephysiological hemodilution of the maternal blood that occurs, and which is most prominent inthe beginning of the third trimester.The cadmium load seemed to increase after a terminated pregnancy. This can, to a largeextent, be explained by an increased absorption of cadmium in the intestine due to aconcomitant increased absorption of iron. In women with two or more children the increase inurinary cadmium with increasing age was more pronounced than in women with none or oneprevious child.Methyl mercury constituted about 75% of the total amount of mercury in the maternal blood.Moreover, it was almost twice as high in the cord blood compared to the maternal blood inlate gestation. The concentration of methyl mercury in cord blood was related to the maternalintake of fresh water fish, while the level of inorganic mercury was related to the maternalnumber of amalgam fillings. The level of inorganic mercury decreased during and afterlactation which can be explained by an elimination to the milk.The levels of lead in cord blood was similar to that of the mother four weeks before delivery.The concentration of maternal blood lead seemed to increase after the terminated pregnancy.This may partly be explained by a higher bone turn over during lactation than duringpregnancy, and thereby an increased release of lead from bone tissue. This will be furtherevaluated in relation to markers of bone metabolism.

Maternal fish intake during pregnancy, blood mercury levels, and child cognition at age 3 years in a US cohort.

Abstract: The balance of contaminant risk and nutritional benefit from maternal prenatal fish consumption for child cognitive development is not known. Using data from a prospective cohort study of 341 mother-child pairs in Massachusetts enrolled in 1999-2002, the authors studied associations of maternal second-trimester fish intake and erythrocyte mercury levels with children's scores on the Peabody Picture Vocabulary Test (PPVT) and Wide Range Assessment of Visual Motor Abilities (WRAVMA) at age 3 years. Mean maternal total fish intake was 1.5 (standard deviation, 1.4) servings/week, and 40 (12%) mothers consumed >2 servings/week. Mean maternal mercury level was 3.8 (standard deviation, 3.8) ng/g. After adjustment using multivariable linear regression, higher fish intake was associated with better child cognitive test performance, and higher mercury levels with poorer test scores. Associations strengthened with inclusion of both fish and mercury: effect estimates for fish intake of >2 servings/week versus never were 2.2 (95% confidence interval (CI): -2.6, 7.0) for the PPVT and 6.4 (95% CI: 2.0, 10.8) for the WRAVMA; for mercury in the top decile, they were -4.5 (95% CI: -8.5, -0.4) for the PPVT and -4.6 (95% CI: -8.3, -0.9) for the WRAVMA. Fish consumption of < or =2 servings/week was not associated with a benefit. Dietary recommendations for pregnant women should incorporate the nutritional benefits as well as the risks of fish intake.

Water Quality Criterion for the Protection of Human Health: Methylmercury

Abstract: This document is the basis for a human health Ambient Water Quality Criterion (AWQC) for methylmercury This AWQC replaces the AWQC for total mercury in published in 1980 and partially updated in 1997 Under Section 304(a) of the Clean Water Act, EPA must periodically revise criteria for water quality to accurately reflect the latest scientific knowledge on the kind and extent of all identifiable effects of pollutants on human health This document uses new methods and information described in the Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health (2000) (2000 Human Health Methodology) (USE PA,2 000a,b) These new methods include updated approaches to determine toxicity dose-response relationships for both carcinogenic and noncarcinogenic effects, updated information for determining exposure factors, and new procedures to determine bioaccumulation factors

Intestinal absorption of dietary cadmium in women depends on body iron stores and fiber intake.

Abstract: Measurements of intake and uptake of cadmium in relation to diet composition were carried out in 57 nonsmoking women, 20-50 years of age. A vegetarian/high-fiber diet and a mixed-diet group were constructed based on results from a food frequency questionnaire. Duplicate diets and the corresponding feces were collected during 4 consecutive days in parallel with dietary recording of type and amount of food ingested for determination of the dietary intake of cadmium and various nutrients. Blood and 24-hr urine samples were collected for determination of cadmium, hemoglobin, ferritin, and zinc. There were no differences in the intake of nutrients between the mixed-diet and the high-fiber diet groups, except for a significantly higher intake of fiber (p < 0.001) and cadmium (p < 0.002) in the high-fiber group. Fecal cadmium corresponded to 98% in the mixed-diet group and 100% in the high-fiber diet group. No differences in blood cadmium (BCd) or urinary cadmium (UCd) between groups could be detected. There was a tendency toward higher BCd and UCd concentrations with increasing fiber intake; however, the concentrations were not statistically significant at the 5% level, indicating an inhibitory effect of fiber on the gastrointestinal absorption of cadmium. Sixty-seven percent of the women had serum ferritin < 30 micrograms/l, indicating reduced body iron stores, which were highly associated with higher BCd (irrespective of fiber intake). BCd was mainly correlated with UCd, serum ferritin, age, anf fibre intake. UCd and serum ferritin explained almost 60% of the variation in BCd.(ABSTRACT TRUNCATED AT 250 WORDS)