Bone-lead analysis: development of analytical methodology for milligram samples.

A graphite platform-in-furnace atomic absorption spectrometric (GFAAS) method for determining micrograms/g levels of Pb in 10-20 mg cortical and trabecular primate bone samples is described. The GFAAS method is based on an ambient temperature nitric acid digestion of the sample, matrix modification with palladium nitrate, stabilized temperature platform furnace atomization, and a systematic evaluation of the temperature program of the atomizer. The method of standard additions is mandatory. The detection limit (3 standard deviations of the blank) is 0.19 micrograms Pb/g dry weight for a 10-mg sample taken up in a 1-mL volume. Data are presented on the degree of accuracy and precision. The accuracy of the proposed GFAAS method has been assessed using the IAEA bone reference material, H-5, and by comparing the values obtained in a bone sample with an isotope dilution mass spectrometric (IDMS) procedure. The GFAAS method can be applied to the determination of Pb in 10-20 mg bone samples and for concentrations which are > or = 10 x detection limit. The method is simple, fast, and contamination-free since the entire operation from weighing to GFAAS measurement is carried out in the same centrifuge tube. The method has been applied to the determination of total-Pb in some adult and fetal primate cortical and trabecular bone specimens.

Lead concentrations in human bones from the Canadian population.

Stable lead was determined in post-mortem samples of human bones from three Canadian cities. All age groups and both sexes were represented. The cities selected for investigation were Winnipeg, Montreal and Charlottetown. No significant difference was found between the locations, although levels tended to be higher for Montreal. Mean lead concentrations (micrograms Pb/g ash) were 8.98 +/- 1.17, 11.11 +/- 1.74 and 8.47 +/- 1.06 for Winnipeg, Montreal and Charlottetown, respectively. Corresponding geometric means were 6.21, 7.88 and 6.71, respectively. Individual values ranged from 0.45 to 240.07 micrograms Pb/g ash. Concentrations were highest in the greater than 20-year age group, indicating increased body burden with age. An increase in lead concentration was observed for the ages 1-11 years with a decrease for the 12-19-year age group. Differences in concentrations between the sexes were not significant. Higher than average concentrations were observed in samples obtained from Winnipeg for the period 1976-1980, particularly in the 1-4-year age group. A similar pattern was observed in the air lead concentrations, suggesting a possible correlation between the concentrations of lead in the air and in bones at Winnipeg.

Respiratory health effects associated with ambient sulfates and ozone in two rural Canadian communities.

A cross-sectional epidemiological study investigating the respiratory health of children in two Canadian communities was conducted in 1983-1984 in Tillsonburg, Ontario, located in a region of moderately elevated concentrations of transported air pollutants, and in Portage la Prairie, Manitoba, situated in a low pollution area. There were no significant local sources of industrial emissions in either community. Seven hundred and thirty-five children aged 7-12 were studied in the first town and 895 in the second. Respiratory health was assessed by the measurement of the forced vital capacity (FVC) and forced expiratory volume in 1 sec (FEV1.0) of each child, and by evaluation of the child's respiratory symptoms and illnesses using a parent-completed questionnaire. Sulfur dioxide (SO2), sulfate, and particulate nitrate levels were significantly higher in Tillsonburg than in Portage la Prairie (P less than 0.05), but nitrogen dioxide (NO2) and inhalable particles (PM10) differed little between the communities. Historical data in the vicinity of Tillsonburg indicated that average annual levels of sulfates, total nitrates, and ozone (O3) did not vary markedly in the 9-year period preceding the study. The results show that Tillsonburg children had statistically significant (P less than 0.001) lower levels of 2% for FVC and 1.7% for FEV1.0 as compared with children in Portage la Prairie. These differences could not be explained by parental smoking or education, the use of gas cooking or wood heating fuels, pollution levels on the day of testing, or differences in age, sex, height, or weight. The differences persisted when children with cough with phlegm, asthma, wheeze, inhalant allergies, or hospitalization before age 2 for a chest illness were excluded from analysis. With the exception of inhalant allergies, which occurred more frequently in Tillsonburg children, the prevalence of chronic respiratory symptoms and illnesses was similar in the two communities.

Non-asbestos fibre content of selected consumer products.

The use of asbestos in consumer products such as joint compounds and modelling clays has been banned since these products, in normal use, have the potential to produce high levels of fibrous dusts in ambient air. However, we were concerned that the asbestos fibres present in these products would be replaced by other fibrous materials. X-ray diffraction and transmission electron microscopy analyses were performed to identify the crystalline components, including mineral fibres, in a selection of 45 samples. Using quantitative X-ray diffractometry, it was established that the fibrous content of several consumer products was in the range of 1-5%. The widespread use of attapulgite in cat litters, joint and spackling compounds and to a lesser extent in art supplies was confirmed. It was also shown that the attapulgite fibres detected were generally in the same size range as chrysotile, with diameters of 0.03-0.5 microns and lengths up to 4 microns.

Indoor-outdoor levels of nitrogen and sulphur species and their relation to air flow in Antigonish, Nova Scotia.

A study was conducted in Antigonish, Nova Scotia, to determine the extent to which acid rain related pollutants are present in indoor ambient air. The pollutant study included: fine (0 to 2.5 micron) and coarse (2.5 to 10 micron) particulates, sulphates, nitrates, acidity (H2SO4 and HNO3), SO2 and NO2. During the 3 1/2 month study, maximum levels of 173n equivalent/m3 fine sulphate and 55 n equivalent/m3 H2SO4 were recorded for outdoor air within the town site compared to corresponding values of 110 n equivalent/m3 and 13 n equivalent/m3 for indoor air. Based on back trajectory analysis, wind direction, and sulphuric acid content, it was postulated that local or medium range pollution sources are predominant in the winter while long range transport originating from the United States produces the major episodes when SW winds are persistent.

Effect of container material, storage time and temperature on determinations of cadmium levels in human urine.

The effect of container material (polyethylene, polypropylene, polystyrene, borosilicate glass and flint glass), storage time (0-86 days), and temperature (22 degrees and 4 degrees ) on the cadmium content found by graphite-furnace atomic-absorption spectrometry for spiked and unspiked urine samples has been studied. No loss of cadmium occurred for at least 10 and 28 days when unspiked and spiked samples respectively, were stored in polyethylene containers at 22 degrees . For storage up to 3-4 days at 22 degrees , polypropylene, polystyrene, borosilicate glass and flint glass containers were also found suitable. Storage at 4 degrees was not effective in preventing loss of cadmium.

Kidney and liver levels of some major, minor and trace elements in two Ontario communities.

The contents of Ag, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, P, Pb, Se, Sr, Th, Ti and Zn in 143 autopsied liver and kidney specimens from two Ontario communities (Kingston and Ottawa) were determined using the techniques of inductively-coupled plasma--atomic emission spectrometry, and electrothermal atomization--atomic absorption spectrometry coupled with hydride evolution (As, Se), reduction--aeration (Hg), or solvent extraction (Pb). The majority of samples came from individuals older than 50 y. In general, the data for the various elements were independent of age or sex but showed some dependence on location for elements such as Cu, Fe, K, Mg, Mn, Na, P, Se and Zn. Despite these differences the elemental values of the liver and kidney samples from both the communities were within the normal range.

Preconcentration of cadmium, chromium, copper and lead in drinking water on the polyacrylic ester resin, XAD-7.

The conditions (e.g. pH, resin, particle size, foreign ions) affecting the uptake of Cd(II), Cr(III), Cu(II) and Pb(II) from aqueous solution by the SM-7 (also called XAD-7) resin, were studied. Based on these studies, a two-column method was developed to overcome the effect of complexation by humic substances. The method was successfully tested with the NBS multielement water standard, SRM 1643a, and was subsequently applied to enrich Cd(II), Cr(III), Cu(II) and Pb(II) in 15 drinking water samples from Hamilton, Ontario. The metals were determined using graphite furnace atomic absorption spectrometry. The results for the drinking water samples showed that leaching of copper and lead occurred from the distribution system.

Arsenic in Nova Scotian groundwater.

The concentration of total soluble inorganic arsenic (i.e. arsenate plus arsenite) was measured in duplicate well water samples of 94 residents in Halifax County, N.S. An ammonium pyrrolidinedithiocarbamate-methyl isobutyl ketone graphite-furnace atomic absorption spectrophotometric procedure and also an automated hydride-evolution electrothermal-atomisation atomic-absorption spectrophotometric method were used to monitor the arsenic level in the ground water supplies. Of the 94 samples analyzed, 66 samples (70%) exceeded the Canadian maximum acceptable drinking water guideline of 50 ng As/ml.

Blood levels of cadmium, copper, lead and zinc in children in a British Columbia community.

The levels of Cd, Cu, Pb and Zn were measured in duplicate whole blood samples of 946 apparently normal children ranging in age from 2 years to 12 years and living in Kamloops, British Columbia, Canada. The metals were determined using atomic absorption spectrometry: graphite furnace AAS for Cd and Pb, and flame AAS for Cu and Zn. The median and extreme values expressed as milligram of metal per litre of whole blood for the total population were: Cd less than or equal to 0.0005, Cu 1.11 (0.69-1.78), Pb 0.112 (0.020-0.400), and Zn 4.30 (2.10-6.53). No significant variations were noted in the median metal values either with age or with sex. The median Cu, Pb and Zn values were within the normal range.

The effect of container material, storage time and temperature on cadmium and lead levels in heparinized human whole blood.

The effect of container material (polycarbonate, polyethylene, polypropylene, polystyrene, borosilicate glass and Pyrex glass), storage time (0, 1, 3, 6, 13, 20, 28 and 60 days), and temperature (22 degrees C, 4 degrees C and -10 degrees C) on cadmium and lead levels in heparinized human whole blood was studied using graphite furnace atomic absorption spectrophotometry. Whole blood samples stored in polycarbonate containers at -10 degrees C did not show significant change in the concentrations of cadmium and lead up to 60 days. Also, the cadmium and lead levels remained unchanged for two weeks when the samples were stored in polyethylene and polypropylene vessels at 4 degrees C.

Determination of arsenic in polluted waters by differential pulse anodic-stripping voltammetry.

Experimental parameters affecting the analytical response of arsenic in differential pulse anodic-stripping voltammetry (DPASV) have been examined. DPASV offers higher sensitivity than linear-scan anodic-stripping voltammetry for similar analysis times. Both techniques have been applied to the NBS Standard Reference Water (SRM 1643) and some polluted water samples. The results on polluted waters compared favourably with those obtained by graphite-furnace atomic-absorption spectroscopy.

Simultaneous determination of 20 elements in some human kidney and liver autopsy samples by inductively-coupled plasma atomic emission spectrometry.

The argon supported inductively coupled plasma--atomic emission spectrometer (ICP--AES) is found to be an attractive analytical tool for the simultaneous multi-element determination of major, minor and trace elements in human liver and kidney specimens. The sample is digested with a mixture of HNO3--HClO4. The damp residue is taken up in HCl, aspirated into the plasma and the resulting emission signals are detected by a polychromator where the analytical lines of the 20 elements determined are included as fixed channels. The method is rapid, precise, sensitive, less subject to interferences and cost-effective. A total of 20 elements in about 40 autopsy samples of human kidney (cortex and medulla) and liver taken from Canadian adults living in the Great Lakes Region of Ontario were determined using the wet digestion-ICP--AES technique.

A rapid electrothermal atomic absorption spectrophotometric method for cadmium and lead in human whole blood.

A rapid graphite-furnace atomic absorption spectrophotometric procedure is described for determining cadmium and lead in heparinized human whole blood. A known aliquot of the blood sample is diluted fivefold with an aqueous solution composed of 5 g each of diammonium hydrogen phosphate and Triton X-100 per liter, the solution is vigorously agitated, and a 10-microL aliquot is injected into a pyrocoated graphite tube under optimized instrumental conditions. Values for Cd and Pb in the sample are obtained by direct comparison to linear working curves prepared from aqueous standards of the metals in the diammonium hydrogen phosphate-Triton medium; there is no need to use the method of standard addition or matrix-matched calibration curves. Also, the method is free of matrix effects. At least 30 samples can be analyzed per hour. The rapidity, simplicity, and sensitivity of the method make it attractive as a screening technique for routine environmental surveillance involving large throughput of samples.

Asbestos and drinking water in Canada.

Samples of raw, treated and distributed tap water were collected from 71 municipalities across Canada and analyzed for asbestos content by transmission electron microscopy. Chrysotile asbestos was identified as the major asbestos type present in drinking water with some 5% of public water supplies containing asbestos at concentrations greater than 10 million fibres per litre. Improvement factors of up to 300 were observed for the removal of chrysotile fibres from drinking water during treatment, indicating that coagulation/filtration treatment is efficient for this purpose. In certain cases there is evidence to suggest that erosion of asbestos from pipe material is taking place. Age-standardized mortality rates for gastro-intestinal cancers were calculated for each city for the period of 1966 to 1976. Rates for the 2 localities with the highest (congruent to 10(8)/L) concentrations of asbestos fibres in treated drinking water were compared with the weighted average of the rates for the 52 localities with asbestos concentrations not significantly greater than zero. Eleven localities had intermediate concentrations of asbestos and six were too small for meaningful statistical analysis. Relatively high mortality rates were apparent amongst males in city 1 for cancer of the large intestine except rectum, and in both sexes in city 1 and males in city 2 for stomach cancer. It is felt that these findings are probably related to occupational exposure to asbestos. Further statistical analyses are required, however, before the significance of these observations can be fully assessed.