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Biomedical subjects

S Skerfving

Publications and source records attributed to S Skerfving.

At least 55 records · Page 3Linked to original sources
PubMed1998

Plasma and blood lead in humans: capacity-limited binding to delta-aminolevulinic acid dehydratase and other lead-binding components.

In 42 lead-exposed workers (22 male and 20 female), we found a close nonlinear relation between blood and plasma lead concentrations, determined by inductively coupled plasma mass spectrometry (ICP-MS). The concentration medians and ranges were lead in whole blood, 270 (97 to 950) micrograms/L and lead in plasma, 1.1 (0.2 to 13) micrograms/L. Proteins from lysed erythrocytes were studied by gel chromatography with ICP-MS detection. We then found capacity-limited binding for lead to delta-aminolevulinic acid dehydratase (ALAD), as well as to two other components (with apparent molecular masses of 45 and < 10 kDa, respectively). The strongest affinity for lead was indicated for ALAD (35-81% of the lead in blood) and could be described by a capacity of 850 micrograms/L and a dissociation constant of 1.5 micrograms/L. The 45-kDa protein carried 12-26% of the blood lead, and the < 10-kDa component less than 1%. A model based on these three components, plus a fourth one for unrecovered lead (2-45%), is proposed. No binding of lead to hemoglobin was found. There was an association between zinc and lead in whole blood; however, zinc did not significantly affect the lead distribution in erythrocytes.

Chromatography, Gel↗
PubMed1998

Cancer predictive value of cytogenetic markers used in occupational health surveillance programs.

It has not previously been clear whether cytogenetic biomarkers in healthy subjects will predict cancer. Earlier analyses of a Nordic and an Italian cohort indicated predictivity for chromosomal aberrations (CAS) but not for sister chromatid exchanges (SCES). A pooled analysis of the updated cohorts, forming a joint study base of 5271 subjects, will now be performed, allowing a more solid evaluation. The importance of potential effect modifiers, such as gender, age at testing, and time since testing, will be evaluated using Poisson regression models. Two other potential effect modifiers, occupational exposures and smoking, will be assessed in a case-referent study within the study base.

Biomarkers↗
PubMed1998

Absence attributed to incapacity and occupational disease/accidents among female and male workers in the fish-processing industry.

Sick-leave between 1984 and 1989 was higher among both female (n = 515) and male (n = 304) fish-processing workers [observed/expected (O/E) 2.24 and 1.69, respectively] than among non-exposed groups (0.62 and 0.89). Diagnoses in the musculoskeletal system dominated (i.e., neck/upper limbs; females, exposed vs. non-exposed workers: 30 vs. 12%; males: 11 vs. 5.8%). In subjects who left employment, the O/E-ratio decreased (females: 3.02 vs. 1.55; males: 2.40 vs. 1.55). Among those women hired before the start of the observation period, exposed subjects had higher frequencies of sick-leave than non-exposed, for both total illness and musculoskeletal diagnoses. In the men, there were corresponding differences, though not fully statistically significant. Reported occupational diseases [O/E: females: 4.5; (95% confidence interval) CI = 3.2-6.1; males: 2.3; CI = 1.3-3.9] and accidents (females: 4.3; CI = 3.0-5.9; males: 1.8; CI = 1.2-2.7) were also higher in female than in male fish-processing workers, and much higher than in non-exposed workers. In conclusion, work in the fish-processing industry was associated with increased frequencies of sick-leave, especially because of diagnoses of the musculoskeletal system, and occupational disorders and accidents, in particular among female workers.

Accidents, Occupational↗
PubMed1998

Methods for health risk assessment of chemicals: are they relevant for alcohol?

A description is given of the principles used for toxicological risk assessment of food additives and environmental contaminants. The terminology is not generally accepted. Hazard identification is to identify whether a substance may cause toxic effects in man. Dose-response assessment is to understand the relationship between exposure and various toxic effects. The shape of dose-response curves is discussed. For most effects (including nongenotoxic carcinogens), a threshold is assumed, under which there is no risk. For genotoxic compounds, no such threshold is assumed. For substances with a threshold, an uncertainty factor is applied to the no-observed-adverse-effect level or the lowest-observed-adverse-effect level, to arrive at an acceptable or tolerable daily intake. In the case of ethanol, some of these principles of toxicological risk assessment may be used and based on epidemiological dose-response data. The critical effects are liver effects, fetal damage, and cancer. All of these effects may be assumed to have thresholds. Possible uncertainty factors are discussed. However, because of the decreased risk of cardiovascular effects at low/moderate intakes and the fact that alcohol intake is a lifestyle factor, it is doubtful whether the application of a no-observed-adverse-effect level/uncertainty factor approach--as used for food additives and environmental pollutants, to which there is unavoidable exposure--is really applicable or meaningful for ethanol.

Alcohol Drinking↗
PubMed1998

Relationship between IgG1 levels and airway responses in guinea pigs actively and passively sensitized to hexahydrophthalic anhydride.

Organic acid anhydrides (OAAs) are industrial chemicals that may cause induction of specific IgE and airway symptoms in exposed workers. They are a good model for studies of relationships between chemical structure and the sensitizing potential of reactive low-molecular-weight compounds. Hexahydrophthalic anhydride (HHPA) is such a compound. This study aimed to evaluate the relationship between specific IgG1 levels and airway responses in a model to predict the sensitizing potential of OAAs. Guinea pigs were either actively or passively sensitized to HHPA. For active sensitization, guinea pigs were injected i.d. with 0.1 ml of olive oil (vehicle) or 0.05, 0.5, or 5% HHPA in olive oil. Passive sensitization was performed by i.p. injection of different volumes of antisera (0.75-6 ml, either unheated to keep IgE or heated to destroy IgE) taken from HHPA-sensitized guinea pigs. Specific antibody levels were evaluated with ELISA and passive cutaneous anaphylaxis. Animals were challenged 16-18 days after active sensitization, or 2 days after passive sensitization, by intratracheal instillation with HHPA conjugated to guinea pig serum albumin (HHPA-GPSA; 0.05% in saline), and the immediate effects on lung resistance (RL), and plasma extravasation, measured as Evans blue dye extravasation, for up to 6 min were recorded. Active sensitization caused production of specific IgG1. Provocation with HHPA-GPSA caused an increase of both RL and Evans blue dye extravasation, which was dependent upon the active sensitization dose. Challenge with HHPA-GPSA in passively sensitized guinea pigs also produced an increase in both RL and Evans blue dye extravasation which was related to the IgG1 level. In the guinea pig model of HHPA-induced airway allergy, the airway responses are closely related to the serum levels of specific IgG1. Thus, the IgG1 levels induced by the immunization may reflect the sensitizing potential of HHPA.

Animals↗
PubMed1998

Lead concentrations in tibial and calcaneal bone in relation to the history of occupational lead exposure.

OBJECTIVES: This study tested a simple model of the relationship between the lead concentration in bone (bone-Pb), exposure time, and lead in plasma (P-Pb) and whole blood (B-Pb) to make it possible to use bone-Pb as a retrospective exposure index. METHODS: Seventy-seven active lead workers and 24 referents were studied. The bone-Pb in tibia (T-Pb) and calcaneus (C-Pb) was measured by in vivo X-ray fluorescence. P-Pb was calculated from B-Pb by use of the nonlinear relationship between these variables. Cumulative B-Pb (cumB-Pb) and P-Pb (cumP-Pb) were calculated to the time of the bone-Pb measurements. In addition, cumP-Pb was adjusted by applying varying rate constants for the transfer of lead from bone to plasma. RESULTS: There were close linear associations between the lead concentrations in tibia (proportion of variance explained, R2 = 0.78) and calcaneus (R2 = 0.80), on one hand and the cumB-Pb on the other. The best fit of bone-Pb to the adjusted cumP-Pb (0.79 for T-Pb; 0.82 for C-Pb) was obtained for the terminal phase half-times of 13 and 12 years, respectively. CONCLUSIONS: The combined data on bone-Pb and exposure time make it possible to estimate previous mean P-Pb and B-Pb. Such estimates will be valuable in studies of toxic effects on long-term exposed lead workers when data on the intensity of previous exposure are lacking. The use of P-Pb in modeling bone-Pb kinetics is physiologically relevant, but the use of adjusted cumP-Pb, as compared with cumB-Pb, did not significantly change the variance in the relation to bone-Pb.

Adolescent↗
PubMed1998

Antibody responses of rats after immunization with organic acid anhydrides as a model of predictive testing.

OBJECTIVES: The sensitizing properties of organic acid anhydrides (OAA) were evaluated in a rat model. METHODS: The development of specific immunoglobulin (Ig)E and Ig G in serum was investigated after immunization with 14 OAA and 3 OAA conjugates. Brown Norway rats were injected intradermally with 0.1 ml of 0.2 M OAA in liquid paraffin or 1.4 mg of rat serum albumin conjugate in saline. Serum samples were collected after 4 weeks. Antibodies were analyzed with enzyme-linked immunosorbent assay. RESULTS: The serum titers of specific Ig E after immunization with the different free OAA varied from <50 to 6400. The rats immunized with 4-methylphthalic anhydride exhibited the highest titers. The specificity of Ig E was demonstrated by enzyme-linked immunosorbent assay inhibition tests. A good correlation was observed between the Ig E and Ig G titers. Immunization with OAA conjugates showed results parallel to the findings for the free compounds. Importantly, the Ig E titers for the OAA agreed well with findings from guinea pigs and with literature data from epidemiologic studies of exposed workers. CONCLUSIONS: The present animal model may be a valuable tool for predicting the sensitizing potential of OAA and possibly the sensitizing potential of low-molecular-weight compounds in general. Furthermore, the antibody specificity of the haptens and the variations in the magnitude of the antibody titers indicate a valuable approach for studies of quantitative structure-activity relationships.

Anhydrides↗
PubMed1997

A neurobehavioural study of long-term occupational inorganic lead exposure.

A group of 38 male workers at a secondary smelter (period of employment 2-35 years; median 10 years) was divided into two subgroups depending on bone-lead concentration, arranged as 19 matched pairs according to age, education and job level. The median concentrations for finger-bone lead (Bone-Pb) were 16 vs. 32 micrograms/g; for current blood-lead (B-Pb), 1.6 vs. 1.8 mumol/1; for retrospective peak blood-lead (Peak-Pb), 2.7 vs. 3.0 mumol/1; and for a retrospective cumulative blood lead index (CBLI), 143 vs. 233 mumol/l x months. Nineteen unexposed male workers from a nearby mechanical plant served as controls, using the same matching algorithm. The triplets were examined with a standardised neuropsychological test battery, and four questionnaires for self-rating of symptoms and activity/stress level related to work environment. No sign of behavioural deterioration was observed in the exposed groups, either in objective cognitive tests or in subjective symptom/mood self-rating scales. Despite the limited sample size, the statistical power was sufficient to conclude that a concealed lead-associated effect was unlikely. Covariations between behavioural measures and lead exposure indices were generally low and non-significant, as a whole not exceeding a random level. No confounding or effect-modifying factor was detected that could explain the results as a type II error. To conclude, a current B-Pb of 1.8 mumol/l was not associated with adverse behavioural effects, and a long-term lead exposure around 2.0 mumol/l for 13 years (mean values) was not associated with permanent brain dysfunction.

Adult↗
PubMed1997

Antibody specificity to the chemical structures of organic acid anhydrides studied by in-vitro and in-vivo methods.

The objective of the study was to evaluate the structure-activity relationship for the antigenic activity of different organic acid anhydrides (OAAs). The specificity of guinea pig (GP) IgG1 to different anhydrides was studied by ELISA-inhibition, PCA, and airway provocation tests of cross-reactivity with different OAA conjugates. In the airway provocation tests, lung resistance and plasma extravasation of Evan's Blue dye was measured. The ELISA-inhibition tests showed a wide range in antibody specificity. Modelling of ring configuration, methyl group substitution, double bond position, and cis/trans isomerism of anhydride forming carboxyl groups influenced the specificity. There was a general consistency in cross-reactivity of anti-cis-hexahydrophthalic anhydride IgG1 versus GP serum albumin conjugates of trans-hexahydrophthalic anhydride, phthalic anhydride, and succinic anhydride as shown by ELISA-inhibition, PCA, and airway provocation tests. It is concluded that various modifications of the chemical structures of a hapten are recognized by the hapten-specific antibodies, and that these differences may have clinical relevance. In particular, the ring structure and the positions of double bonds and of methyl groups are important. Further, the in-vitro ELISA-inhibition tests show a good agreement with the in-vivo PCA and bronchial provocation tests.

Airway Resistance↗
PubMed1997

In vivo measurements of lead in fingerbone in active and retired lead smelters.

OBJECT: The aim of this study was to determine the bone lead concentration in lead smelters and reference subjects, relate them to the lead concentration in blood (B-Pb) and urine (U-Pb), and to use the measured bone lead to calculate a biological half-life for lead in bone. METHOD AND DESIGN: The lead concentration in the second phalanx of the left index finger (bone-Pb) was determined in vivo using an X-ray fluorescence technique. The study population comprised 89 smelters with a history of long-term exposure to lead (71 active and 18 retired) and 35 reference subjects (27 active and 8 retired) with no known occupational exposure to lead. Bone-Pb was related to the previous lead exposure, estimated as a time-integrated B-Pb (CBLI). RESULTS: The retired smelters had the highest bone-Pb (median value 55 micrograms/g wet weight, as against 23 micrograms/g in active smelters) and 3 micrograms/g in the reference subjects. A strong positive correlation was observed between the bone-Pb and the CBLI among both active (rs = 0.73; P < 0.001) and retired (rs = 0.71; P = 0.001) smelters. The corresponding correlations between the bone-Pb and the period of employment were of the same magnitude. For retired workers, there were positive correlations between the bone-Pb and the B-Pb (rs = 0.58; P = 0.011) and U-Pb. (rs = 0.56; P = 0.02). Multiple regression analyses showed that bone-Pb was best described by the CBLI, which explained 29% of the observed variance (multiple r2) in bone-Pb in active workers and about 39% in retired workers. The estimated biological half-life of bone-Pb among active lead workers was 5.2 years (95% confidence interval 3.3-13.0 years). CONCLUSIONS: The high bone-Pb seen in retired workers can be explained by the long exposure periods, the higher exposure levels in earlier decades, and the slow excretion of lead accumulated in bone. The importance of the skeletal lead pool as an endogenous source of lead exposure in retired smelters was indicated by the associations between the B-Pb or U-Pb, on the one hand, and the bone-Pb, on the other. In active workers, the ongoing occupational exposure was dominant. The in vivo X-ray fluorescence technique is still mainly a research tool, and more work has to be done before it can be used more widely in clinical practice. However, over the next decade we can anticipate retrospective, prospective and cross-sectional epidemiological studies in which bone lead determinations reflecting the previous lead exposure in both occupationally and nonoccupationally lead exposed populations are related to various types of adverse health outcomes. Such studies will improve our knowledge of dose-response patterns and provide data that will have an impact on hygienic threshold limit values and prevention of lead-induced diseases.

Adult↗
PubMed1997

Quantifying work load in neck, shoulders and wrists in female dentists.

OBJECTIVE: To assess the work load in neck and upper limbs of dentists. METHODS: Twelve right-handed female dentists (six with and six without a history of definite neck/shoulder disorders, pair-wise matched for age) were studied when performing authentic dental work. Electromyography (EMG) was used to quantify the muscular load of the shoulders bilaterally and of the right forearm. Positions and movements of the head and wrists were measured, using inclinometers and electrogoniometers. RESULTS: During work, the median load for the right upper trapezium muscle was 8.4% of the maximal voluntary EMG activity (MVE); during 90% of the time the load was > or = 3.3% MVE ("static" load). The figures were somewhat lower on the left side (7.0% and 2.5% MVE, respectively). Subjects with disorders had over all lower load levels for the trapezius muscles, although not statistically significant at < 0.05, than those without disorders. During a standardized reference contraction for the trapezius, the load was 17% MVE, and the quotient between MVE and torque [normalized to maximal voluntary torque (MVC)] was 0.5. These figures may be used for transformations. The muscular load on the right forearm was similar to the loads on the trapezius. The head was, on average, forward tilted > or = to 39 degrees, and during 10% of the time > or = 49 degrees. The left hand was held in more static positions, with palmar flexion and ulnar deviation, also reflected by lower angular velocities and repetitiveness, as compared with the right one, which was dorsiflexed. CONCLUSIONS: Dentists are exposed to high load on the trapezius muscles bilaterally, and steep, prolonged forward bending of the head. Further, for the wrists the postures were constrained, but the dynamic demands were low.

Adult↗
PubMed1997

Extensive lead exposure in children living in an area with production of lead-glazed tiles in the Ecuadorian Andes.

We have determined the concentrations of lead (Pb), cadmium (Cd), and mercury (Hg) in the blood of children living in two Andean villages in Ecuador with many family-owned cottage-type industries using Pb from discarded car batteries and occasionally, utility batteries containing Cd and Hg for the production of glazed tiles. The battery metals are ground together with water to a suspension, which is applied manually onto the tiles and then fused at about 1,200 degrees C in sawdust-fired kilns. Children aged 4-15 years were recruited from the schools with the assistance of the school-teachers. Children from homes with and without tile-glazing activities were to be included. Blood metal concentrations were determined by inductively coupled plasma mass spectrometry (ICP-MS). The children had extremely high blood lead concentrations (B-Pb), which ranged between 100 and 1,100 micrograms/l (median 510 micrograms/l, n = 82). Children from families engaged in tile-glazing production had significantly higher B-Pb (median 600 micrograms/l) than those living in homes with no such activity (median 210 micrograms/l), although the B-Pb of the latter were nonetheless clearly elevated. B-Cd and B-Hg were low (medians 0.25 microgram Cd/l and 1.6 micrograms Hg/l, respectively), indicating that the exposure from utility batteries containing Cd and Hg was low. The blood hemoglobin concentrations decreased significantly with rising B-Pb, indicating an effect on the heme synthesis. This was supported by a marked increase in the blood concentration of protoporphyrins with increasing B-Pb. It can be concluded that children from families with cottage industries producing glazed tiles are at risk for severe health effects due to high lead exposure.

Adolescent↗
PubMed1997

Childhood asthma in four regions in Scandinavia: risk factors and avoidance effects.

BACKGROUND: The high and increasing prevalence of childhood asthma is a major public health issue. Various risk factors have been proposed in local studies with different designs. METHODS: We have made a questionnaire study of the prevalence of childhood asthma, potential risk factors and their relations in four regions in Scandinavia (Umeå and Malmö in Sweden, Kuopio in eastern Finland and Oslo, Norway). One urban and one less urbanized area were selected in each region, and a study group of 15962 children aged 6-12 years was recruited. RESULTS: The prevalence of symptoms suggestive of asthma varied considerably between different areas (dry cough 8-19%, asthma attacks 4-8%, physician-diagnosed asthma 4-9%), as did the potential risk factors. Urban residency was generally not a risk factor. However, dry cough was common in the most traffic polluted area. Exposure to some of the risk factors. such as smoking indoors and moisture stains or moulds at home during the first 2 years of life, resulted in an increased risk. However, current exposure was associated with odds ratios less than one. CONCLUSIONS: Our findings were probably due to a combination of early impact and later avoidance of these risk factors. The effects of some risk factors were found to differ significantly between regions. No overall pattern between air pollution and asthma was seen, but air pollution differed less than expected between the areas.

Air Pollution↗
PubMed1997

Lead binding to delta-aminolevulinic acid dehydratase (ALAD) in human erythrocytes.

Over 99% of the lead present in blood is usually found in erythrocytes. To investigate the nature of this selective accumulation of lead in erythrocytes, the specific binding of lead to proteins in human erythrocytes was studied using liquid chromatography coupled to inductively coupled plasma mass spectrometry (LC-ICP-MS). The principal lead-binding protein had a mass of approximately 240 kDa, and adsorption to specific antibodies showed that protein was delta-aminolevulinic acid dehydratase (ALAD). Thus, the previous notion that lead in erythrocytes was bound primarily to haemoglobin has to be revised. Furthermore, in lead-exposed workers, the percentage of lead bound to ALAD was influenced by a common polymorphism in the ALAD gene. Specifically, in seven carriers of the ALAD2 allele, 84% of the protein-bound lead recovered was bound to ALAD compared to 81% in seven homozygotes for the ALAD1 allele whose erythrocytes were matched for blood-lead concentration. The small difference was statistically significant in Wilcoxon matched-pairs signed-rank test (P = 0.03). No ALAD allele-specific difference in ALAD-bound lead was found among 20 unexposed controls. Perhaps the difference in ALAD-bound lead can provide an explanation for the previously reported finding of higher blood-lead levels among carriers of the ALAD2 allele than among ALAD1 homozygotes in lead-exposed populations.

Adult↗
PubMed1997

Deaths and tumours among workers grinding stainless steel: a follow up.

OBJECTIVE: To study cause specific mortality and cancer morbidity in workers exposed to the dust of grinding materials, grinding agents, and stainless steel, especially with regard to a possibly increased risk of respiratory, stomach, and colorectal cancer. METHODS: Retrospective cohort study, using reference cohorts of blue collar workers and population rates for comparison. The exposed cohort comprises workers with at least 12 months employment time at two plants, producing stainless steel sinks and saucepans (n = 727). Also, reference cohorts of other industrial workers (n = 3965) and fishermen (n = 8092) were analysed. The observation period began 15 years after the start of employment. Standardised mortality or incidence ratios (SMRs, SIRs; county reference rates) were calculated for cause-specific mortality between 1952 and 1993, and for cancer morbidity between 1958 and 1992. RESULTS: In the exposed cohort, overall mortality, cardiovascular mortality, and all malignant mortality and morbidity were slightly lower than expected. Also, the risk estimates for cancer in the upper and lower respiratory tracts and for stomach cancer were lower than expected. There was an increase in morbidity from colon cancer, which was explained by an excess of tumours in the sigmoid part only. Here, the risk estimates were higher in workers with long employment time (1-14 years: four observed cases, SIR 1.7, 95% confidence interval (95% CI) 0.4 to 4.5; > or = 15 years: three observed cases, SIR 4.3, 95% CI 0.9 to 13) and the increased risk was especially pronounced among those first employed before 1942. A slight nominal excess of rectal cancers (nine observed cases, SIR 1.4, 95% CI 0.6 to 2.6), and a significant excess of prostate cancer morbidity (36 observed cases, SIR 1.7, 95% CI 1.2 to 2.4) were found. These risk estimates did not, however, increase with employment time. CONCLUSIONS: The finding of an increased risk of cancer in the sigmoid part of the colon, which was not found in the reference cohorts, and with indication of a relation between duration of employment and response, is consistent with a causal relation. The limited size of the exposed cohort makes a detailed exposure-response analysis unstable, and the confidence limits are wide. Albeit slightly raised, the risk estimate for rectal cancer in the exposed cohort was not different from the estimate among the other industrial workers.

Case-Control Studies↗
PubMed1997

High lead exposure and auditory sensory-neural function in Andean children.

We investigated blood lead (B-Pb) and mercury (B-Hg) levels and auditory sensory-neural function in 62 Andean school children living in a Pb-contaminated area of Ecuador and 14 children in a neighboring gold mining area with no known Pb exposure. The median B-Pb level for 62 children in the Pb-exposed group was 52.6 micrograms/dl (range 9.9-110.0 micrograms/dl) compared with 6.4 micrograms/dl (range 3.9-12.0 micrograms/dl) for the children in the non-Pb exposed group; the differences were statistically significant (p < 0.001). Auditory thresholds for the Pb-exposed group were normal at the pure tone frequencies of 0.25-8 kHz over the entire range of B-Pb levels, Auditory brain stem response tests in seven children with high B-Pb levels showed normal absolute peak and interpeak latencies. The median B-Hg levels were 0.16 micrograms/dl (range 0.04-0.58 micrograms/dl) for children in the Pb-exposed group and 0.22 micrograms/dl (range 0.1-0.44 micrograms/dl) for children in the non-Pb exposed gold mining area, and showed no significant relationship to auditory function.

Adolescent↗
PubMed1997

Lead concentrations in human plasma, urine and whole blood.

OBJECTIVES: Blood-lead levels (B-Pb), and to some extent urinary lead (U-Pb), are the most employed measures of lead exposure and risk. However, the small fraction of lead present in plasma (usually below 1% of that in blood) is probably more relevant to lead exposure and toxicity. Nevertheless, the lead content of plasma lead (P-Pb) has only seldom been used, mainly due to analytical limitations, which have now been overcome. We examined P-Pb in occupationally exposed subjects, as well as its relationship with B-Pb and U-Pb. METHODS: Blood samples were obtained from 145 male workers, 110 of whom were employed in lead work. After a simple dilution of plasma, P-Pb was determined by inductively coupled plasma mass spectrometry. The detection limit was 0.04 microg/l, and the imprecision was 5%. RESULTS: The lead concentration ranges were 0.20-37 microg/l for P-Pb, 0.9-176 microg/l (density adjusted) for U-Pb, and 9-930 microg/l for B-Pb. A close exponential relation was obtained between B-Pb and P-Pb. When B-Pb was plotted versus log P-Pb, a straight line (log P-Pb = 0.00225 x B-Pb - 0.58; r = 0.97) was obtained. Both the relation between U-Pb and P-Pb and that between U-Pb and B-Pb showed a large scattering (r = 0.78 in both cases). The relation to B-Pb appeared to be exponential, while that to P-Pb appeared to be linear. CONCLUSIONS: The low detection limit and good precision of P-Pb determinations make it possible to use P-Pb in assessments of lead exposure and risk. Furthermore, in relative terms, P-Pb is a more sensitive measure than B-Pb, especially at high lead levels. This development is of importance for studies of exposure, possibly also for studies of risks.

Adult↗