1998 and beyond--Legge's legacy to modern occupational health.
Thomas Legge achieved much in his professional lifetime. The purpose of this lecture is to highlight some of these achievements in the light of what we have achieved since then. In other words, if Legge was in the audience today, how would he feel we have performed? On 'industrial maladies', progress has been made in reducing poisoning by heavy metals but our success with chrome ulceration and lead depends on surveillance and control. Room for improvements remain. For asbestos related diseases, Legge would be disappointed with our progress. Two areas of particular concern to Legge were upper limb disorders and 'occupational neurosis'. Much remains to be done. As a member of the 1st Committee on Compensatable Diseases, a review of the Scheme to date will focus on the common diseases now being prescribed and on the threats to the Scheme from the Benefits review. For the future, there are many challenges in the newer workplaces and the changing workforces. The HSE initiatives for a new occupational strategy and the Government Green Paper on Public Health provide great opportunities for the occupational health professional to influence the nature and shape of future public health strategy. Above all we must have some of Legge's characteristics to achieve this-vision, passion and commitment. (+info)
Lead and hypertension in a sample of middle-aged women.
OBJECTIVES: The role of lead exposure as a risk factor for hypertension is less well defined among women than among men. This case-control study assessed the relation of blood and bone lead concentrations to hypertension in women. METHODS: Cases and controls were a subsample of women from the Nurses' Health Study. Hypertension was defined as a physician diagnosis of hypertension between 1988 and 1994 or measured systolic blood pressure > or = 140 mm Hg or diastolic blood pressure > or = 90 mm Hg. RESULTS: Mean (SD) blood lead concentration was 0.15 (0.11) mumol/L; mean tibia and patella lead concentrations by K-x-ray fluorescence were 13.3 (9.0) and 17.3 (11.1) micrograms/g, respectively. After adjustment for potentially confounding factors, an increase from the 10th to the 90th percentile of patella lead values (25 micrograms/g) was associated with approximately 2-fold (95% confidence interval = 1.1, 3.2) increased risk of hypertension. There was no association between hypertension and either blood or tibia lead concentrations. CONCLUSIONS: These findings support a potentially important role for low-level lead exposure as a risk factor for hypertension among non-occupationally exposed women. (+info)
Experimental canine distemper infection as a means of demonstrating latent effects of subacute lead intoxication.
Observations on the response of the body to experimental infection with distemper virus in dogs previously dosed subacutely with lead have demonstrated a latent effect of lead on several body systems. Effects which indicated a relationship to earlier treatment with lead included evidence for stimulation of haemoglobin synthesis, changes to red blood cells resulting in increased destruction, increased vulnerability of the parenchymatous cells of the liver to damage, reduction in the weight of the skeleton and thyroid, an increase in weight of the thymus and brain and histopathological changes in the thymus. (+info)
Adult Blood Lead Epidemiology and Surveillance--United States, second and third quarters, 1998, and annual 1994-1997.
Chronic lead exposure in adults can damage the cardiovascular, central nervous, renal, reproductive, and hematologic systems. CDC's Adult Blood Lead Epidemiology and Surveillance (ABLES) program monitors laboratory-reported elevated blood lead levels (BLLs) among adults in the United States. During 1998, 27 states reported surveillance data to ABLES. This report presents prevalence data for elevated BLLs for the second and third quarters of 1998 and compares them with corresponding quarters of 1997, and presents annual prevalence data for elevated BLLs from 1994 through 1997 for each participating state. The findings indicate that of the approximately 20,000 persons tested for blood lead and reported to ABLES each quarter, approximately 4000 BLLs were elevated. The 1994-1997 prevalence rates of elevated BLLs among adults provide a crude comparison of the levels and trends among the 27 states participating in the program. (+info)
Relationships between lead absorption and peripheral nerve conduction velocities in lead workers.
The motor sensory, and mixed nerve conduction velocities of median and posterior tibial nerves were measured in 39 lead workers whose blood lead (PbB) concentrations ranged from 2 to 73 mug/100 g with anaverage of 29 mug/100 g. The PbB concentrations significantly correlated with the maximal motor nerve conduction velocities (MCV) and mixed nerve conduction velocities (MNCV) of the median nerve in the forearm and with the MCV of the posterior tibial nerve. Erythrocyte delta-aminolevulinic acid dehydratase (ALAD) activity correlated similarly with the MCV and MNCV of the median nerve in the forearm, and the 24-hour urinary lead excretion following the intravenous administration of CaEDTA (20 mg/kg) (lead mobilization test) correlated with the MNCV. But no parameter correlated with the sensory nerve conduction velocities. By multiple regression analysis, a combination of the three parameters of lead absorption was found to correlate significantly with the MCV and MNCV of the median nerve in the forearm. The MCVs of the median and posterior tibial nerves in lead workers were significantly delayed in the PbB range of 29-73 mug/100 g (mean 45), in the lead mobilization test range from 173 to 3,540 mug/day (mean 973), and the ALAD activity range from 4.4 to 19.4 u. (mean 14.0), respectively. (+info)
Lifetime low-level exposure to environmental lead and children's emotional and behavioral development at ages 11-13 years. The Port Pirie Cohort Study.
The Port Pirie Cohort Study is the first study to monitor prospectively the association between lifetime blood lead exposure and the prevalence of emotional and behavioral problems experienced by children. Lead exposure data along with ratings on the Child Behavior Checklist were obtained for 322 11-13-year-old children from the lead smelting community of Port Pirie, Australia. Mean total behavior problem score (95% confidence interval (CI)) for boys whose lifetime average blood lead concentration was above 15 microg/dl was 28.7 (24.6-32.8) compared with 21.1 (17.5-24.8) in boys with lower exposure levels. The corresponding mean scores (95% CI) for girls were 29.7 (25.3-34.2) and 18.0 (14.7-21.3). After controlling for a number of confounding variables, including the quality of the child's HOME environment (assessed by Home Observation for Measurement of the Environment), maternal psychopathology, and the child's IQ, regression modeling predicted that for a hypothetical increase in lifetime blood lead exposure from 10 to 30 microg/dl, the externalizing behavior problem score would increase by 3.5 in boys (95% CI 1.6-5.4), and by 1.8 (95% CI -0.1 to 11.1) in girls. Internalizing behavior problem scores were predicted to rise by 2.1 (95% CI 0.0-4.2) in girls but by only 0.8 (95% CI -0.9 to 2.4) in boys. (+info)
Comparison of the entropy technique with two other techniques for detecting disease clustering using data from children with high blood lead levels.
The entropy technique was compared with two other case-control techniques for detecting disease clustering using data on blood lead levels of children who were patients at the King/Drew Medical Center in South-Central Los Angeles in 1991 to 1994. The other two methods are the nearest neighbor technique (NNT) and Moran's IPOP technique, a variation of Moran's I test, in which rates are adjusted for population size. Four different blood lead levels (15 microg/dl, 20 microg/dl, 30 microg/dl, 35 microg/dl) were used as cutoff levels to designate cases. Persons with blood lead levels greater than or equal to the cutoff level were designated as cases. The authors found significant clustering for all four cutoff levels using the entropy method, and for the first three cutoff levels using the NNT. They found significant clustering with Moran's IPOP for some scales for two of the cutoff levels. While performance of the entropy technique and the NNT were independent of scale, that of Moran's IPOP was highly scale-dependent. (+info)
Testing their metal.
Metals continually rank at the top of the U.S. Environmental Protection Agency's annual list of agents that pose the greatest hazard to the people of the United States. Metals aren't going away, either. They do not biodegrade, and they often concentrate in human and animal cells and tissue. Many metals are known human and animal carcinogens, while many others are suspected to play a role in cancer. Little is known, however, about the mechanisms by which metals cause cancer. (+info)