PubMed HealthSearch

Biomedical subjects

C Edling

Publications and source records attributed to C Edling.

At least 19 recordsLinked to original sources

Alkaline single cell gel electrophoresis of DNA fragments in biomonitoring for genotoxicity: an introductory study on healthy human volunteers.

Alkaline single cell gel electrophoresis (also known as the 'comet assay') is a rapid method for detecting DNA strand breaks in individual cells. Before the assay is used for biomonitoring in human populations the test conditions must be accurately characterised. Five healthy male volunteers donating capillary blood over a period of 20 weeks showed a fairly stable level of DNA damage in their lymphocytes. The values for tail moment and tail inertia, as evaluated by computerised image analysis of coded samples, were similar to those in lymphocytes from control mice but only 10% of those in lymphocytes from mice given cyclophosphamide (200 mg/kg b.wt.) 15-17 h before sacrifice. Inter- and intraindividual variations among the human subjects were related to both individual factors and laboratory conditions. When the comet assay is used for biomonitoring purposes it is suggested that each electrophoresis session should include not only the coded samples from the subjects, but also freshly isolated control cells and, in addition, cells that have been exposed to a well-characterised genotoxic insult.

Adult

Do organic solvents induce changes in the dopaminergic system? Positron emission tomography studies of occupationally exposed subjects.

OBJECTIVES: The objective of this study was to test the hypothesis that long-term occupational exposure to organic solvents may effect the levels and turnover of dopamine in man. METHODS: A study was performed on 17 patients with neuropsychiatric symptoms due to occupational solvent exposure, and 11 healthy non-exposed male volunteers (controls). Positron emission tomography (PET) was used to assess striatal dopaminergic function, using L-[11C]DOPA, [11C]nomifensine and [11C]raclopride as tracers. RESULTS: The rate of dopamine synthesis was significantly increased among subjects with occupational exposure to organic solvents compared with non-exposed controls. After controlling for the difference in age between exposed and controls, the effect of solvent exposure became less apparent and was reduced from +32% (P = 0.009) to +25% (P = 0.07). There were no differences with regard to the binding of [11C]nomifensine. Patients with and without the diagnosis of toxic encephalopathy did not differ with regard to their putaminal uptake of L-[11C]DOPA, [11C]nomifensine and [11C]raclopride. CONCLUSION: The data support the hypothesis that long-term exposure to organic solvents may increase the rate of dopamine synthesis in the brain without affecting the number of presynaptic terminals or postsynaptic dopamine receptors.

Brain

Airway symptoms among house painters in relation to exposure to volatile organic compounds (VOCS)--a longitudinal study.

The increased use of water-based paint (WBP) for indoor application during the last decade has drastically changed the exposure conditions for Swedish house painters. WBP has a lower emission of volatile organic compounds (VOCs) than solvent-based paint (SBP), but contains more reactive compounds, such as biocides, glycol ethers, and other high molecular solvents. The aim of this study was to compare the incidence of airway symptoms and self-reported asthma in house painters with a different degree of use of WBP and SBP. The incidence of seven general airway symptoms, and three work-related symptoms, was analysed by means of a self-administered questionnaire, in a cohort of 207 house painters followed from 1989 to 1992. Different airway symptoms were compared with clinical information obtained by a methacholine challenge test and dynamic spirometry in a selected subgroup of 44 painters. Information on the degree of use of SBP and WBP was used to estimate the total exposure to volatile organic compounds (TVOC) for each individual. In total, 175 men in the cohort worked as painters during the study period. No increase of asthma or respiratory symptoms was observed among those 50 painters with a pure exposure to WBP (estimated TVOC 1-3 mg m-3). Most painters (N = 125) had a mixed exposure to SBP and WBP, the main source of the TVOC being the limited use of SBP. WBP was perceived as less irritative than SBP, but complaints on airway irritation from WBP increased during the study period. The most pronounced increase of airway irritation in relation to both SBP and WBP, was observed among those 35 painters with the highest solvent exposure (estimated TVOC 100-380 mg m-3). An increase of respiratory symptom index and shortness of breath, in relation to estimated TVOC exposure was also observed. Selection effects were detected. Painters leaving their job during the study period had more non-specific hyper-reactivity symptoms, and more airway irritation from WBP, as compared to painters remaining at their occupation. Our study indicates that VOC emissions from SBPs may contribute to the development of respiratory symptoms and airway irritation. We found no increase of respiratory symptoms among painters exposed only to WBPs. There were, however, indications that VOC exposure from WBPs may cause airway irritation in some subjects. Because of selection effects, cross-sectional studies on respiratory symptoms in relation to occupational exposure to paint emissions may be inconclusive.

Adult

No increased DNA damage in peripheral lymphocytes of sewage workers as evaluated by alkaline single cell gel electrophoresis.

OBJECTIVES: To study whether sewage workers are exposed to genotoxic substances. An increased risk of cancers among sewage workers has been noted. If this increased risk is due to an exposure to genotoxic agents, primarily DNA damage could be used as a biological marker of exposure. METHODS: In a cross sectional study, DNA damage in peripheral lymphocytes from 35 sewage workers and 30 controls was compared with alkaline single cell gel electrophoresis, a technique for detecting single strand breaks and alkali labile sites in DNA. The controls were selected from among municipal workers matched for age and smoking habit. Information about occupational exposures and possible confounders was collected by means of a questionnaire. RESULTS: No increase in DNA damage was found among the sewage workers when compared with the unexposed controls. CONCLUSIONS: The failure to detect increased damage to DNA in peripheral lymphocytes by alkaline single cell gel electrophoresis suggests that the sewage workers studied here were not exposed to genotoxic agents to a greater extent than other municipal workers. It may be, however, that the lymphocyte is not the appropriate target cell to study, or that sewage workers are exposed to carcinogens which do not damage the genetic material.

Animals

Occupational exposure to organic solvents and sleep-disordered breathing.

STUDY OBJECTIVE: To investigate whether people with occupational exposure to organic solvents have a higher prevalence of obstructive sleep apnea syndrome (OSAS) than the general population and to examine the relationship between snoring and exposure to organic solvents. DESIGN AND PARTICIPANTS: Consecutive patients, aged 30-64 years, referred during a 3-year period to the sleep laboratory at Avesta Hospital, Sweden, because of suspected OSAS made up the patient groups. Following admission, patients underwent a simplified sleep apnea investigation and were divided into two groups, OSAS (n = 320) and snorers (n = 443). A random sample of 296 men and 289 women aged 30-64 years obtained from a register of all country residents maintained by the county tax authority served as referents (controls). Both patients and referents responded to two questionnaires, including questions about occupation, exposure to organic solvents, and other chemical and physical agents. RESULTS: Men with OSAS or snoring and women with snoring had more often been occupationally exposed to organic solvents than the referents, showing an almost twofold increase in risk for those exposed during whole workdays. For men, the risk of OSAS or snoring increased with increasing exposure. CONCLUSION: The result indicates that occupational exposure to organic solvents might cause sleep apnea. A new observation is that even snoring could be caused by exposure to organic solvents. It is important to elucidate whether exposure to organic solvents is a cause of OSAS, because such a finding may have important implications for prevention and treatment of sleep disturbances.

Adult

Positron emission tomography studies of healthy volunteers--no effects on the dopamine terminals and synthesis after short-term exposure to toluene.

Despite extensive research, the mechanisms for the effects of organic solvents on the central nervous system are still unknown. One mechanism proposed is that solvents interfere with the synthesis of neurotransmitters. In the present study 11 male healthy volunteers were exposed during 15 min to 100 p.p.m. toluene at light physical exercise, and the dopamine decarboxylase activity and number of terminals in putamen were measured before and after exposure by positron emission tomography. Two different tracers were used [beta-11C]L-DOPA for decarboxylase activity during the in vivo synthesis of dopamine, and [11C]nomifensine to estimate the number of terminals. Although there was a slight increase in the rate of dopamine synthesis in the putamen after the exposure, this difference was not statistically significant (P = 0.4). No effect was observed with regard to the uptake of nomifensine. There was no significant relationship between the dose of toluene and rate of dopamine synthesis, and no significant correlation between the time from end of exposure to start of the PET-camera and DOPA. Our findings indicate that short term exposure to 100 p.p.m. of toluene does not affect the rate of dopamine synthesis or the number of presynaptic terminals.

Adult

Estimating lung cancer mortality from residential radon using data for low exposures of miners.

Some recent estimates of lung cancer risk from exposure to radon progeny in homes have been based on models developed from a pooled analysis of 11 cohorts of underground miners exposed to radon. While some miners were exposed to over 10,000 working level months (WLM), mean exposure among exposed miners was 162 WLM, about 10 times the exposure from lifetime residence in an average house and about three times the exposure from lifetime residence at the "action level" suggested by the U.S. Environmental Protection Agency. The extrapolation of lung cancer risk from the higher exposures in the miners to the generally lower exposures in the home is a substantial source of uncertainty in the assessment of the risk of indoor radon. Using the pooled data for the miners, analyses of lung cancer risk were carried out on data restricted to lower exposures, either <50 WLM or <100 WLM. In the pooled data, there were 115 lung cancer cases among workers with no occupational WLM exposure and 2,674 among exposed miners, with 353 and 562 lung cancer cases in miners with <50 WLM and <100 WLM, respectively. Relative risks (RRs) for categories of WLM based on deciles exhibited a statistically significant increasing trend with exposure in each of the restricted data sets. In the restricted data, there was little evidence of departures from a linear excess relative risk model in cumulative exposure, although power to assess alternative exposure-response trends was limited. The general patterns of declining excess RR per WLM with attained age, time since exposure and exposure rate seen in the unrestricted data were similar to the patterns found in the restricted data. Risk models based on the unrestricted data for miners provided an excellent fit to the restricted data, suggesting substantial internal validity in the projection of risk from miners with high exposures to those with low exposures. Estimates of attributable risk for lung cancer (10-14%) in the U.S. from residential radon based on models from the unrestricted data were similar to estimates based on the data for miners receiving low exposures.

Air Pollutants, Radioactive

Asthma among secondary schoolchildren in relation to the school environment.

BACKGROUND: Poor indoor air quality has been suggested to be related to the increase in the prevalence of asthma that has occurred in the western world, especially among children and young persons. Apart from the home, school is the most important indoor environment for children. OBJECTIVES: The aims were to study the prevalence of current asthma among secondary pupils and its relationship to the school environment, but also to personal factors and domestic exposures. METHODS: Data on asthmatic symptoms, other health aspects, and domestic exposures were gathered using a questionnaire which was sent to 762 pupils in the seventh form (13-14 years old) in 11 randomly chosen schools in the county of Uppsala in Sweden. Pupils answering 'yes' to having had asthma diagnosed by a physician, and having had recent asthma attacks, or who used asthma medication were defined as having current asthma. Data on exposures at school were gathered by measurements in 28 classrooms. The relationship between asthma and exposures was analysed by multiple logistic regression. RESULTS: The questionnaire was completed by 627 (82%). Current asthma was found among 40 pupils (6.4%). Current asthma was more common in those who had an atopic disposition, or food allergy, or who had attended a day care centre for several years. Controlling for these factors, current asthma was related to several factors in the school environment. There were more pupils with current asthma in schools that were larger, had more open shelves, lower room temperature, higher relative air humidity, higher concentrations of formaldehyde or other volatile organic compounds, viable moulds or bacteria or more cat allergen in the settled dust. CONCLUSIONS: Although the pupils attended school for a minor part of their time, our study indicates that the quality of the school environment is of importance and may affect asthmatic symptoms.

Adolescent

Headache, snoring and sleep apnoea.

To evaluate reported headache prevalence among the general population and patients suffering from snoring and obstructive sleep apnoea syndrome (OSAS), a cross-sectional study was performed among those aged 30-64 years residing in Kopparberg county in central Sweden. Consecutive patients referred to the sleep laboratory in the catchment area who fulfilled objective diagnostic criteria (snorers = 448, OSAS = 324) and a random sample of the general population (n = 583) responded to the same questionnaire. Patients were selected following sleep apnoea screening with 100% specificity for both OSAS and snoring. Responders from the general population were divided into snorers or non-snorers on the basis of self-report. To validate the self-report question on snoring in the questionnaire, 50 males and 49 females, randomly selected from the sample of the general population, underwent sleep apnoea screening in their homes. Headache among both men and women was found to be more prevalent among heavy snorers and OSAS patients compared with the control group. Morning headache, in particular, was at least three times more common among male and female heavy snorers and OSAS patients then among the general population. Headache in the control group was more common among snorers than non-snorers. Among responders, 5% of the general population reported experiencing headache often or very often upon awakening. For the heavy snoring and OSAS groups, 18% reported experiencing headache often or very often upon awakening. The results indicate that headache is common among heavy snorers and OSAS patients regardless of gender.

Adult

Local cold exposure of the hands from cryosectioning work in histopathological and toxicological laboratories: signs and symptoms of peripheral neuropathy and Raynaud's phenomenon.

OBJECTIVES: To study relations between cryosectioning work, skin temperature, early signs of neuropathy in the hands, and vasospastic and neurological symptoms. Microtome work is carried out at histological and toxicological laboratories all over the world. It implicates local cold exposure of -20 degrees C on the hands of exposed laboratory technicians. METHODS: Thirty nine laboratory technicians who use microtomes at the preclinical and clinical laboratories at the University of Uppsala, Sweden were studied. An equal number of nonexposed laboratory technicians served as controls, matched for workplace, sex, age, and smoking habits. Information on symptoms, type of work, and personal factors were assessed by means of a self administered questionnaire. Two point discrimination ability was tested, and vibration perception threshholds were measured for both hands by a bio-thesiometer. Also, skin temperature was measured during cryosectioning work in those 15 technicians performing cryosectioning work during the study period. RESULTS: Most laboratory technicians did not use any gloves during cryosectioning work, and direct contact with frozen materials sometimes occurred and resulted in a rapid cooling of the skin. In six of 15 exposed subjects (40%), the mean skin temperature during microtome work was below 20 degrees C. A later rise in skin temperature, due to a compensatory vasodilation, was found in two subjects. The group exposed to cold had signs of early neuropathy on the right hand, indicated both by vibrametry and two point discrimination test. Significant work related differences in clinical signs within the group exposed to cold was also found. No differences between exposed and nonexposed people were found for symptoms of Raynaud's phenomenon, numbness, or musculosceletal complaints. CONCLUSION: Our study shows that cryosectioning laboratory work may cause adverse health effects--for example, peripheral neuropathy--and measures should be taken to protect the hands from the local cold exposure.

Adult

Excessive daytime sleepiness at work and subjective work performance in the general population and among heavy snorers and patients with obstructive sleep apnea.

STUDY OBJECTIVE: To evaluate excessive daytime sleepiness (EDS) at work and effects on reported work performance among men in the general population and male patients suffering from snoring and obstructive sleep apnea syndrome (OSAS). DESIGN AND PARTICIPANTS: A cross-sectional study of Swedish men between the ages of 30 and 64 years in the county of Kopparberg, in mid-Sweden. A random sample of the general population (n = 285) and consecutive patients referred to a sleep laboratory who fulfilled objective diagnostic criteria (snorers = 289, OSAS = 62) responded to a questionnaire. Responders from the general population were divided into 2 groups, nonsnorers (n = 223) and snorers (n = 62). To validate a question on snoring in the questionnaire, 50 men, randomly selected from the sample of the general population, underwent sleep apnea screening in their homes. RESULTS: The specificity of the questions about snoring was 83% and the sensitivity was 42%. The risk ratios for reporting EDS at work were 4-fold for snorers in the general population, 20-fold for snoring patients, and 40-fold for patients with OSAS as compared with nonsnoring men in the general population. Patients with OSAS and snoring patients both showed increased ratios on measures of difficulties with concentration, learning new tasks, and performing monotonous tasks when compared with nonsnorers. CONCLUSION: Snoring and sleep apnea were highly associated with excessive EDS at work and subjective work performance problems. The results provide additional evidence that snoring is not merely a nuisance.

Adult

Prevalence of Helicobacter pylori infection among sewage workers.

OBJECTIVES: An increased risk for gastric cancer among sewage workers has been described in several studies. During the last decade the bacterium Helicobacter pylori has emerged as one important risk factor for gastric cancer and is now considered a class I carcinogen by the International Agency for Research on Cancer. The route of transmission for this bacterium remains unclear, but fecal-oral transmission has been proposed. If true, this might entail a yet undescribed risk for sewage workers. METHOD: The prevalence of immunoglobulin G (IgG) antibodies against H pylori was studied with a cross-sectional study design in a group of 289 municipal workers. Samples of serum from 151 sewage workers at 11 sewage plants in Sweden and of serum from 138 referents were analyzed. The referents were group matched for age and socioeconomic status. RESULTS: The prevalence of IgG antibodies against H pylori among sewage workers did not differ from that of the referents. The adjusted odds ratio (adjOR) was calculated from a logistic model with age and residence as confounding variables (adjOR 0.90, 95% confidence interval 0.53-1.5). The previously described increase in the prevalence of IgG antibodies against H pylori with increasing age was observed. Geographic differences were also observed in the prevalence of H pylori in Sweden. CONCLUSIONS: The exposures in sewage work in Sweden do not cause an increased risk of infection with H pylori.

Adult

Neck and shoulder ailments in a group of female industrial workers with monotonous work.

The aim of the present paper was to study the comprehension of exposure to different physical and psycho-social factors at work, at home and during leisure time and the lifestyle of a group of unskilled female workers, and also their reports of musculoskeletal ailments, especially in the neck, shoulders and thoracic back. Furthermore an evaluation of the relevance of the methods used and the validity of the results are discussed. One hundred and seventy-three women, aged 20-45 years, from, in total, 26 large, medium-sized and small enterprises in three counties in Sweden participated in the study. Each woman answered a questionnaire in the presence of the project leader in a separate room close to her workplace. The questionnaires comprised questions on demographic, work-related and domestic factors; smoking habits, lifestyle and level of physical activity, leisure activities, health status and musculoskeletal problems. The prevalence of musculoskeletal ailments and the smoking habits among the 173 women was compared to a group of 153 women of the same age from the general population. The environmental factors reported as being most disturbing at work were noise, temperature and humidity, and the most frequent adverse physical factors were repetition of movements, precision and uncomfortable posture. The women in the studied group were largely responsible for domestic tasks such as laundry, cleaning and cooking but to a greater extent shared the responsibility for the children with their partners. The highest prevalence of ailments in the study group were in the neck (68%) and shoulders (74%); in the group from the general population these prevalences were 35 and 42%, respectively. The relevance of methods used and the validity of the results were found to be acceptable.

Adult

Lung cancer in radon-exposed miners and estimation of risk from indoor exposure.

BACKGROUND: Radioactive radon is an inert gas that can migrate from soils and rocks and accumulate in enclosed areas, such as homes and underground mines. Studies of miners show that exposure to radon decay products causes lung cancer. Consequently, it is of public health interest to estimate accurately the consequences of daily, low-level exposure in homes to this known carcinogen. Epidemiologic studies of residential radon exposure are burdened by an inability to estimate exposure accurately, low total exposure, and subsequent small excess risks. As a result, the studies have been inconclusive to date. Estimates of the hazard posed by residential radon have been based on analyses of data on miners, with recent estimates based on a pooling of four occupational cohort studies of miners, including 360 lung cancer deaths. PURPOSE: To more fully describe the lung cancer risk in radon-exposed miners, we pooled original data from 11 studies of radon-exposed underground miners, conducted a comprehensive analysis, and developed models for estimating radon-associated lung cancer risk. METHODS: We pooled original data from 11 cohort studies of radon-exposed underground miners, including 65,000 men and more than 2700 lung cancer deaths, and fit various relative risk (RR) regression models. RESULTS: The RR relationship for cumulative radon progeny exposure was consistently linear in the range of miner exposures, suggesting that exposures at lower levels, such as in homes, would carry some risk. The exposure-response trend for never-smokers was threefold the trend for smokers, indicating a greater RR for exposure in never-smokers. The RR from exposure diminished with time since the exposure occurred. For equal total exposure, exposures of long duration (and low rate) were more harmful than exposures of short duration (and high rate). CONCLUSIONS: In the miners, about 40% of all lung cancer deaths may be due to radon progeny exposure, 70% of lung cancer deaths in never-smokers, and 39% of lung cancer deaths in smokers. In the United States, 10% of all lung cancer deaths might be due to indoor radon exposure, 11% of lung cancer deaths in smokers, and 30% of lung cancer deaths in never-smokers. This risk model estimates that reducing radon in all homes exceeding the U. S. Environmental Protection Agency's recommended action level may reduce lung cancer deaths about 2%-4%. These estimates should be interpreted with caution, because concomitant exposures of miners to agents such as arsenic or diesel exhaust may modify the radon effect and, when considered together with other differences between homes and mines, might reduce the generalizability of findings in miners.

Adult

Radon-exposed underground miners and inverse dose-rate (protraction enhancement) effects.

Recent models for radon-induced lung cancer assume that at high levels of cumulative exposure, as experienced historically by many underground miners of uranium and other ores, the risk of lung cancer follows an inverse dose-rate (protraction enhancement) pattern. That is, for equal total dose, a greater risk is incurred by those whose total dose is accumulated at a lower rate over a longer duration than at a higher rate over a shorter duration. This inverse dose-rate effect is hypothesized to be the consequence of multiple traversals of the nucleus of a target cell by alpha particles. It has recently been concluded, however, that for low total doses, as in most residential settings, the inverse dose-rate effect should diminish and perhaps even disappear, since at very low doses the probability that more than one alpha particle would traverse a cell is small and there would be no possibility for interactions from multiple hits. Pooling original data from 11 cohort studies of underground miners, including nearly 1.2 million person-y of observation and 2,701 lung cancer deaths, we evaluate the presence of an inverse dose-rate effect and its modification by total dose. An inverse dose-rate effect was confirmed in each cohort, except one, and overall in the pooled data. There also appears to be a diminution of the inverse dose-rate effect below 50 Working Level Months (WLM), although analyses were necessarily hampered by a limited range of exposure rates at low total WLM. These data support both the presence of an inverse dose-rate effect, as well as its diminution at low total dose. As a consequence, assessment of risks of radon progeny exposure in homes (on average 15-20 WLM for a lifetime) using miner-based models should not assume an ever-increasing risk per unit dose. Rather, it is more appropriate to apply risk models that take into account protraction enhancement and its diminution.

Humans

Skin disease and contact sensitivity in house painters using water-based paints, glues and putties.

A dermatologic investigation of 202 construction painters included patch testing with the TRUE Test standard series and ingredients of water-based paints, glues and putties (painters' series). 32 painters had current eczema and 16 had a history of previous eczema. Of these, 16 and 9, respectively, had current and previous histories of hand eczema. Irritant reactions on the hands, characterized by dry, erythematous finely fissured skin, which healed within a few days of skin rest, were found in 18 painters. 8 painters presented dry, fissured finger tips and finger sides. The total group of painters had 25 allergic reactions to the TRUE Test standard series and 11 to the painters' series. 11 test reactions were found to be related to present or previous hand eczema: 4 cases reacted to nickel, cobalt, colophony or N-octyl-isothiazolinone; 2 each to p-tertbutylphenol-formaldehyde resin and benzisothiazolinone (BIT); and 3 to Cl + Me-isothiazolinone. 5 painters were sensitive to BIT without clinical symptoms of skin disease. Hand eczema is no more common among construction painters who work with water-based paints, glues and putties, than in an average population. There are, however, special risks of sensitization and eczema in a construction painter's work that should be considered on employment.

Adhesives

Cancer incidence among pharmaceutical workers.

OBJECTIVES: A cluster of cancers at one plant in a pharmaceutical company in Sweden was the initiator for this work, which describes the cancer incidence among the laboratory and production workers at this company. METHODS: The investigation is a retrospective cohort study. All employees with possible exposure to chemical, pharmacological, or biological agents and employment for at least six months at the company during 1960-1990 were included. Standardized incidence ratios (SIR) were calculated with the local county population as reference. RESULTS: The total cancer incidence was close to the expected. In a subcohort consisting of the highest exposed employees, an SIR of 3.5 [95% confidence interval (95% CI) 1.5-6.8] was found for urothelial tumors, while there were no urothelial tumors among the workers with the lowest exposure. An evaluation of the exposures among the subjects with urothelial tumors revealed no association with specific exposures in the workplaces. There was also a statistically significant increase in the risk for acute leukemia (SIR 4.5, 95% CI 1.2-12 ). With a 10-year induction-latency period in the calculations, the elevated risk was smaller and not significant. Although the numbers were small, there were also statistically significant overrisks for cancer of the peritoneum, the lip, and the pleura. CONCLUSIONS: A significant increase in the risk for urothelial tumors was found among pharmaceutical workers. All but one of those with urothelial tumors were smokers, but confounding from smoking could probably not explain the risk increase.

Acute Disease

Lead intoxication caused by skeletal disease.

BACKGROUND: Inorganic lead is accumulated in the skeleton, which harbors more than 90% of the body burden of lead. If rapidly mobilized, this pool may constitute a health risk. However, clear evidence of this theory has been lacking. HISTORY: A previously healthy 36-year-old Swedish man with more than 10 years of work-related lead exposure developed headache, musculoskeletal pain, and paresthesia of both arms. Two months after the cessation of exposure, the lead level in his blood (B-Pb) was 5.5 mumol.l-1, and treatment with chelating agents was started. Shortly after the treatment period, he had an accident causing a fracture of the right collum femoris. The B-Pb was fairly stable around 1.5 mumol.l-1 for about two years after the end of exposure (95th percentile 0.6 mumol.l-1 for occupationally unexposed Swedish men). The examination showed that the patient had high skeletal turnover and clearly reduced bone density, as well as signs of tubular dysfunction. He was given the diagnosis idiopathic osteoporosis. His moderately raised bone lead concentration (about 20 micrograms.g wet weight-1; normal level in Sweden 4 micrograms.g-1) can only partly explain the raised B-Pb, remaining for years after the cessation of exposure. Instead, the main explanation is probably the increased skeletal turnover. CONCLUSIONS: A combination of a moderately increased bone lead pool and skeletal disease seems to increase the risk for lead poisoning.

Adult