Interviews were previously conducted with 72 heroin-addicted female street prostitutes who spread HIV by sharing injection paraphernalia and engaging in unprotected sex with multiple male customers. Most were willing to enroll in free methadone maintenance if made available. Forty-one female addict-prostitutes subsequently entered free methadone maintenance. Twenty-five remained in treatment after one year. Their personal income from prostitution and other crime was reduced 58%; income from legal sources increased 86%. Total urinalyses positive for non-prescribed drugs decreased from 80% on admission to 51%. This pilot study validates the attraction of free methadone maintenance and concomitant reduction of illegal drug use and prostitution, two predictors of HIV infection. However, close supervision and effective counseling and rehabilitative services provided by better trained staff are required for successful outcomes among addict-prostitutes in methadone maintenance.

No abstract

ICP-MS analysis recorded historical change (c. 1846 to 2002) in the arsenic concentration of bark included within the trunks (tree bark pockets) of two Japanese oak trees (Quercus crispula), collected at an elevated location approximately 10 km from the Ashio copper mine and smelter, Japan. The arsenic concentration of the bark pockets was 0.016 +/- 0.003 microg cm(-2) c. 1846 (n = 5) and rose 50-fold from c. 1875 to c. 1925, from approximately 0.01 to 0.5 microg cm(-2). The rise coincided with increased copper production in Ashio from local sulfide ores, from 46 tons per year in 1877 to 16,500 tons per year in 1929. Following a decline in arsenic concentration and copper production, in particular during the Second World War, a second peak was observed c. 1970, corresponding to high levels of production from both local (6,000 tons per year) and imported (30,000 tons per year) ores, smelted from 1954. Compared to the local ores, the contribution of arsenic from imported ores appeared relatively low. Arsenic concentrations declined from c. 1970 to the present following the closure of the mine in 1974 and smelter in 1989, recording 0.058 +/- 0.040 microg cm(-2) arsenic (n = 5) in surface bark collected in 2002. The coincident trends in arsenic concentration and copper production indicated that the bark pockets provided an effective record of historical change in atmospheric arsenic deposition.

No abstract

SummaryLead accumulates in bone over many years or decades. Accordingly, the study of lead in bone is important in determining the fate of ingested lead, the potential for remobilization, and for the application of bone lead measurements as a biomarker of lead exposure. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used to measure the spatial distribution of lead in bone on the micrometer scale. In general, LA-ICP-MS studies are somewhat limited by the lack of matrix-matched standards and/or reference materials for calibration and validation purposes. Here we describe the application of pressed pellets prepared from New York State Department of Health candidate Reference Materials for Lead in Bone (levels 1 through 4), to provide a linear calibration for 208 Pb/ 43 Ca in the concentration range <1 to 30 μg g −1 . The limit of detection was estimated as 0.2 μg g −1 . The measured lead values for pelletized NIST SRM 1486 Bone Meal and SRM 1400 Bone Ash were in good agreement with certified reference values. Using this approach, we quantitatively measured the spatial distribution of lead in a cross-section of goat metacarpal from a lead-dosed animal. The lead content was spatially variable in the range of 2 to 30 μg g −1 with a complex distribution. In some sections, lead appeared to be enriched in the center of the bone relative to peripheral areas, indicating preferential accumulation in trabecular (spongy) rather than cortical bone. In addition, there were discrete areas of lead enrichment, or hot spots, of 100 to 200 μm in width.

No abstract

Teeth are commonly used as a biomarker of long-term lead exposure. There appear to be few data, however, on the content or distribution of lead in teeth where data on specific lead intake (dose) are also available. This study describes the analysis of a convenience sample of teeth from animals that were dosed with lead for other purposes, i.e., a proficiency testing program for blood lead. Lead concentration of whole teeth obtained from 23 animals, as determined by atomic absorption spectrometry, varied from 0.6 to 80 μg g −1 . Linear regression of whole tooth lead (μg g −1 ) on the cumulative lead dose received by the animal (g) yielded a slope of 1.2, with r 2 = 0.647 (p<0.0001).Laser ablation inductively coupled plasma mass spectrometry was employed to determine lead content at micrometer scale spatial resolution in the teeth of seven goats representing the dosing range. Highly localized concentrations of lead, ranging from about 10 to 2000 μg g −1 , were found in circumpulpal dentine. Linear regression of circumpulpal lead (μg g −1 ) on cumulative lead dose (g) yielded a slope of 23 with r 2 = 0.961 (p = 0.0001). The data indicated that whole tooth lead, and especially circumpulpal lead, of dosed goats increased linearly with cumulative lead exposure. These data suggest that circumpulpal dentine is a better biomarker of cumulative lead exposure than is whole tooth lead, at least for lead-dosed goats.

The increasing emission of Pt-group metals from automobile catalytic converters requires the development of highly sensitive procedures for ultratrace analysis of environmental and biological systems. Tree bark, located close to motorway or industrial areas, was utilised as a substrate for collection of airborne particulate matter and samples after digestion (microwave assisted dissolution with HNO3 and HCl) were analysed by ICP mass spectrometry. The study targeted Pt and other metallic contaminants and involved analysis of some 57 tree bark samples using both quadrupole and double-focusing sector field ICP mass spectrometers. Detection limits for platinum determination in tree bark were 0.03 ng/g (DF-ICP-MS) and 0.2 ng/g (ICP-QMS). The platinum content of the bark samples ranged from 0.07-5.4 ng/g.