A study was conducted to compare the blood lead levels of 97 pregnant women warded at the Kuala Lumpur Hospital, according to their ethnicity, residence and place of work. The lead content of venous blood samples was determined with a graphic furnace atomic absorption spectrometer. Blood lead levels of Klang Valley women seem to have decreased from 17.3 micrograms/dl in 1982 to 7.71 micrograms/dl in the present study most probably attributed to the phasing out of leaded gasoline. This level is below the 10 micrograms/dl recommended by the United States Environmental Protection Agency for the public, even though 27.8% of them still have blood lead levels that are equal to or in excess of 10 micrograms/dl. The study shows that certain segments of the population such as Indians (geometric mean = 9.35 micrograms/dl) and housewives (geometric mean = 9.55 micrograms/dl) may still experience blood lead levels that are slightly elevated than the rest of the population.
Objective: Lead toxicity constitutes a major environmental risk to health in both animals and humans of all ages. It is more severe in young children than adults. Blood transfusion is an important source of lead exposure and may predispose premature infants to lead toxicity. Thalassaemia is common in Malaysia and majority of patients require frequent blood transfusion. The objective of this study was to determine whether regular blood transfusion contributed to high blood lead levels in paediatric thalassaemic patients.
Method: This was a cross sectional study conducted at the Paediatric Thalassaemia Day Care Unit, General Paediatric Ward and Paediatric Clinic in Hospital Universiti Sains Malaysia (HUSM). A total of 90 patients were included, 45 were thalassaemic transfusion dependant patients and the other 45 were control, who were of the same age and sex with patients group and had never been transfused. The blood samples were taken preand post-transfusion for thalassaemic and control groups. Blood lead levels were analyzed using standard Atomic Absorption Spectrometer (AAS) analysis.
Results: The overall mean plasma lead levels (2.13 + 1.72µg/dL) were lower than those of standard CDC recommendations. The independent t-test showed that plasma lead levels in thalassaemic group were significantly (p < 0.05) lower than the levels in controls. However, the ANCOVA analysis revealed the plasma lead levels were not significantly (p > 0.05) different between the two groups. Thus, suggesting that the reduced plasma lead level in thalassaemic group was due to the administration of iron chelators. Increased frequency of blood transfusion also did not significantly (p > 0.05) increase plasma ferritin or lead levels in thalassaemic patients.
Conclusion: This study shows that transfusion dependent thalassaemic infants have comparable plasma lead levels to those of age- and sex-matched controls, after taking into consideration the administration of iron chelators.
Study site: Paediatric Thalassaemia Day Care Unit, General Paediatric Ward and Paediatric Clinic in Hospital Universiti Sains Malaysia (HUSM)
A cross-sectional study was conducted to identify the relationship between blood lead concentration and nutritional status among primary school children in Kuala Lumpur. A total of 225 Malay students, 113 male and 112 female, aged 6.3 to 9.8 were selected through a stratified random sampling method. The random blood samples were collected and blood lead concentration was measured by a Graphite Furnace Atomic Absorption Spectrophotometer. The nutrient intake was determined by the 24-hour Dietary Recall method and Food Frequency Questionnaire. An anthropometric assessment was reported according to growth indices (z-scores of weight-for-age, height-for-age, and weight-for-height). The mean blood lead concentration was low (3.4 +/- 1.91 ug/dL) and was significantly different between gender. Only 14.7% of the respondents fulfilled the daily energy requirement. The protein and iron intakes were adequate for a majority of the children. However, 34.7% of the total children showed inadequate intake of calcium. The energy, protein, fat and carbohydrate intakes were significantly different by gender, that is, males had better intake than females. Majority of respondents had normal mean z-score of growth indices. Ten percent of the respondents were underweight, 2.8% wasted and 5.4% stunted. Multiple linear regression showed inverse significant relationships between blood lead concentration with children's age (beta = -0.647, p < 0.001) and per capita income (beta = -0.001, p = 0.018). There were inverse significant relationships between blood lead concentration with children's age (beta = -0.877, p = 0.001) and calcium intake (beta = -0.011, p = 0.014) and positive significant relationship with weight-for-height (beta = 0.326, p = 0.041) among those with inadequate calcium intake. Among children with inadequate energy intake, children's age (beta = -0.621, p < 0.001), per capita income (beta = -0.001, p = 0.025) and protein intake (beta = -0.019, p = 0.027) were inversely and significantly related with blood lead concentration. In conclusion, nutritional status might affect the children's absorption of lead and further investigation is required for confirmation.
This study aimed to determine the relationship between blood lead (BPb) concentrations and cognitive and physical development in school children. A total of 169 urban children and 100 industrial children of Malay ethnicity, in the age range of 6(1/2) to 8(1/2) years, were selected. BPb was determined using GF atomic absorption spectrophotometer. The mean cognitive score (102.55) of the children from the industrial area was significantly higher than that of the urban children (95.09; P < .001). However, no significant differences were found in the BPb levels between the 2 groups (industrial, 3.75 microg/dL; urban, 3.56 microg/dL). There was significant inverse correlation between BPb and cognitive scores for all children (P < .05). The cognitive scores for all children were influenced by BPb after adjustments (P < .05). The urban children had significantly better Weight for Height and Left Arm Circumference values than those from industrial area. There was no significant correlation between BPb and the anthropometric measurements. In conclusion, low BPb influenced the cognitive development, whereas physical development was not affected.
Blood lead levels of two ethnic groups (11 Chinese and 25 Malays) of workers in a factory manufacturing lead accumulator battery were studied. The mean adjusted (for environmental lead levels, age, exposure duration and stick-years of smoking by analysis of covariance) blood lead level of the Malays was 34.8 micrograms/dl as compared to 22.4 micrograms/dl for the Chinese. This difference was significant (p less than 0.02). Oral ingestion of lead, through eating of food with hands contaminated by lead compound, among the Malay workers was suggested as a possible cause for the difference in the mean blood lead levels. Preventive measures and recommendations to overcome the problem among this particular group of workers were discussed.
The present study was conducted to evaluate the role of ingestion through hand and mouth contamination in the absorption of lead in 25 lead-acid battery workers. Levels of personal exposure to airborne lead ranged from 0.004 to 2.58 mg/m3 [geometric mean 0.098, with 25% of samples exceeding threshold limit values (ACGIH) of 0.15 mg/m3]; the mean (SD) blood lead level was 48.9 (10.8) micrograms/dl. Mean hand lead contents increased 33-fold from preshift levels on Monday mornings (33.5 micrograms/500 ml) to midshift levels on Thursday afternoons (1121 micrograms/500 ml). Mouth lead contents increased 16-fold from 0.021 micrograms/50 ml on Mondays to 0.345 micrograms/50 ml on Thursdays. The typical Malay racial habit of feeding with bare hands and fingers without utensils (closely associated with mouth and hand lead levels on Mondays) explained the bulk of the variance in blood lead levels (40%), with mouth lead on Thursdays (closely associated with poor personal hygiene) explaining a further 10%. Air lead was not a significant explanatory variable. The implementation of a programme of reinforcing hand-washing and mouth-rinsing practices resulted in a reduction of the blood lead level by 11.5% 6 months later. These results indicate that parenteral intake from hand and mouth contamination is an important cause of lead absorption in lead-exposed workers.
A novel synthesis and characterization of cellulose, hydroxyapatite and chemically-modified carbon electrode (Cellulose-HAp-CME) composite was reported for the analysis of trace Pb(II) ions detection and its validation in blood serum. The Field Emission Scanning Electron Microscopy (FESEM) analyses showed that the composite retained the orderly porous structure but with scattered particle size agglomeration. The Fourier Transform Infrared Spectroscopy (FTIR) spectra suggested the presence of functional groups associated with the bending and stretching of carbon bonds and intermolecular H-bonding. X-ray Diffraction (XRD) analyses further elucidated that the crystallite size could have influenced the properties of the electrode. Based on Thermo-gravimetric Analysis (TGA/DTG), the composites showed thermal stability with more than 60% residual content at 700°C. The sensor was successfully developed for trace Pb(II) ions detection in complex medium such as blood serum, in the physiologically relevant range of 10-60ppb, with resulting Limit of Detection (LOD) of 0.11±0.36ppb and Limit of Quantification (LOQ) of 0.36±0.36ppb. The newly fabricated electrode could be advantageous as a sensing platform with favourable electrochemical characteristics for robust, in situ and rapid environmental and clinical analyses of heavy metal ions.
Though most childhood lead exposure in the USA results from ingestion of lead-based paint dust, non-paint sources are increasingly implicated. We present interdisciplinary findings from and policy implications of a case of elevated blood lead (13-18 mcg/dL, reference level <5 mcg/dL) in a 9-month-old infant, linked to a non-commercial Malaysian folk diaper powder. Analyses showed the powder contains 62 % lead by weight (primarily lead oxide) and elevated antimony [1000 parts per million (ppm)], arsenic (55 ppm), bismuth (110 ppm), and thallium (31 ppm). These metals are highly bioaccessible in simulated gastric fluids, but only slightly bioaccessible in simulated lung fluids and simulated urine, suggesting that the primary lead exposure routes were ingestion via hand-mouth transmission and ingestion of inhaled dusts cleared from the respiratory tract. Four weeks after discontinuing use of the powder, the infant's venous blood lead level was 8 mcg/dL. Unregulated, imported folk remedies can be a source of toxicant exposure. Additional research on import policy, product regulation, public health surveillance, and culturally sensitive risk communication is needed to develop efficacious risk reduction strategies in the USA. The more widespread use of contaminated folk remedies in the countries from which they originate is a substantial concern.
A survey was conducted between 1995 and 1997 to assess the impact of introduction of unleaded petrol and other public health measures on the blood lead level of the population. The geometric mean blood lead level of 269 government employees as determined by graphite furnace atomic absorption spectroscopy, was 66.0 microg/l, much lower than that recorded before introduction of lead-free petrol. Using multiple regression analysis, factors significantly associated with blood lead levels were: exposure to traffic, age (>50 years) and active smoking. Passive smoking, exposure to recent paint work, consumption of alcohol and traditional medicine were found not to be significantly associated with the blood lead level.
The objective of this article is to study the influence of exposure and socio-economic variables on the blood lead level of Malaysian school children. Data on respirable lead and blood lead of 346 school children were obtained from Kuala Lumpur (urban), Kemaman (semi-urban) and Setiu (rural). Respirable lead and blood lead were highest for Kuala Lumpur (95 ng/m3 and 5.26 micrograms/dL) followed by Kemaman (27 ng/m3 and 2.81 micrograms/dL) and Setiu (15 ng/m3 and 2.49 micrograms/dL), and the differences were statistically significant. The percentage of school children with excessive blood lead of 10 micrograms/dL or greater was 6.36% overall, and highest for Kuala Lumpur (11.73%). Regression analyses show that urban children are at higher risk of exhibiting excessive blood lead levels. Kuala Lumpur's school children have a 25 times greater risk of having excessive blood lead levels when compared to Kemaman's and Setiu's school children. Respirable and blood lead were correlated (r = 0.999, p = 0.021). Urban school children acquire higher blood lead levels than their rural and semi-urban counterparts, even after controlling for age, sex, parents' education and income levels. In conclusion, it is time that lead in the Malaysian environment and population be monitored closely, especially its temporal and spatial variability. Only then can a comprehensive preventive strategy be implemented.
This study was conducted as part of the Human Exposure Assessment Location (HEAL) Project which comes under the United Nations Environment Programme/World Health Organisation (UNEP/WHO) Global environmental Monitoring System (GEMS). The objective of the study was to evaluate workers' exposure to lead in industries with the highest exposure. All subjects were interviewed about their occupational and smoking histories, the use of personal protective equipment and personal hygiene. The contribution of a dietary source of lead intake from specified foods known to contain lead locally and personal air sampling for lead were assessed. A total of 61 workers from two PVC compounding and 50 workers from two lead acid battery manufacturing plants were studied together with 111 matched controls. In the PVC compounding plants the mean lead-in-air level was 0.0357 mg/m3, with the highest levels occurring during the pouring and mixing operations. This was lower than the mean lead-in-air level of 0.0886 mg/m3 in the lead battery manufacturing plants where the highest exposure was in the loading of lead ingots into milling machines. Workers in lead battery manufacturing had significantly higher mean blood lead than the PVC workers (means, 32.51 and 23.91 mcg/100 ml respectively), but there was poor correlation with lead-in-air levels. Among the lead workers, the Malays had significantly higher blood lead levels than the Chinese (mean blood levels were 33.03 and 25.35 mcg/100 ml respectively) although there was no significant difference between the two ethnic groups in the control group. There were no significant differences between the exposed and control group in terms of dietary intake of specified local foods known to contain lead. However, Malays consumed significantly more fish than the Chinese did. There were no ethnic differences in the hours of overtime work, number of years of exposure, usage of gloves and respirators and smoking habits. Among the Malays, 94.3% eat with their hands compared with 9.2% of the Chinese. Workers who ate with bare hands at least once a week had higher blood lead levels after adjusting for lead-in-air levels (mean blood lead was 30.2 and 26.4 mcg/100 ml respectively). The study indicated that the higher blood lead levels observed in the Malay workers might have been due to their higher exposure and eating with bare hands.
Several environmental toxins with toxic effects to the bone marrow have been identified. Pathology associated with lead intoxication is due to the cellular damage mediated by free radicals. In the current study, we examined the effect of Etlingera elatior extract on lead-induced changes in the oxidative biomarkers and histology of bone marrow of rats. Sprague-Dawley rats were exposed to 500 ppm lead acetate in their drinking water for 14 days. E. elatior extract was treated orally (100mg/kg body weight) in combination with, or after lead acetate treatment. The results showed that there was a significant increase in lipid hydroperoxide, protein carbonyl content and a significant decrease in total antioxidants, super oxide dismutase, glutathione peroxidase and glutathione--S-transferase in bone marrow after lead acetate exposure. Treatment with E. elatior decreased lipid hydroperoxides and protein carbonyl contents and significantly increased total antioxidants and antioxidant enzymes. Treatments with E. elatior extract also reduced, lead-induced histopathological damage in bone marrow. In conclusion, these data suggest that E. elatior has a powerful antioxidant effect, and it protects the lead acetate-induced bone marrow oxidative damage in rats.