Maternal and neonatal lead exposure in southern Italy

BACKGROUND: Over the past 20 years, there has been remarkable improvement in the chances of survival of patients treated in burn centers. A simple, accurate system for objectively estimating the probability of death would be useful in counseling patients and making medical decisions. METHODS: We conducted a retrospective review of all 1665 patients with acute burn injuries admitted from 1990 to 1994 to Massachusetts General Hospital and the Shriners Burns Institute in Boston. Using logistic-regression analysis, we developed probability estimates for the prediction of mortality based on a minimal set of well-defined variables. The resulting mortality formula was used to determine whether changes in mortality have occurred since 1984, and it was tested prospectively on all 530 patients with acute burn injuries admitted in 1995 or 1996. RESULTS: Of the 1665 patients (mean [+/-SD] age, 21+/-20 years; mean burn size, 14+/-20 percent of body-surface area), 1598 (96 percent) lived to discharge. The mean length of stay was 21+/-29 days. Three risk factors for death were identified: age greater than 60 years, more than 40 percent of body-surface area burned, and inhalation injury. The mortality formula we developed predicts 0.3 percent, 3 percent, 33 percent, or approximately 90 percent mortality, depending on whether zero, one, two, or three risk factors are present. The results of the prospective test of the formula were similar. A large increase in the proportion of patients who chose not to be resuscitated complicated comparisons of mortality over time. CONCLUSIONS: The probability of mortality after burns is low and can be predicted soon after injury on the basis of simple, objective clinical criteria.     

Hemorheology in occupational lead exposure

OBJECTIVES: The purpose of this investigation was to study hemorheological parameters in occupationally lead exposed men. MATERIAL AND METHODS: For 15 clinically healthy lead-exposed male subjects [age 34.6 (SD 8) years] the viscous (epsilon') and elastic (epsilon") components of whole blood viscosity corrected for 45% hematocrit were measured for shear rates between 1.s-1-100.s-1 at 37 degrees C. Moreover, lead concentrations in blood and urine and the delta-aminolevulinic acid dehydrase level were determined. Fifteen unexposed age-matched men were used as referents. RESULTS: The mean lead concentration in the blood and urine of the lead-exposed men was 48.7 (SD 16.2) micrograms. dl-1 and 38.8 (SD 17.1) micrograms.g creatinine-1, respectively. While epsilon" was significantly increased only at low shear rates, epsilon' was elevated throughout the investigated shear range in comparison with the values of the unexposed referents. These results are characteristic of erythrocytes with enhanced rigidity. The aggregation and filtration index of erythrocytes were significantly elevated for the lead-exposed workers. A positive correlation existed between lead in blood and epsilon' or epsilon", whereas delta -aminolevulinic acid dehydrase and epsilon' or epsilon" were inversely correlated. No differences in plasma viscosity or in lipid status could be detected. CONCLUSION: Increased blood lead concentrations can be considered an additional risk factor for vascular diseases predisposing towards microvascular occlusion.     

Occupational lead exposure and management

We report a series of 60 children operated on for posterior urethral valve (PUV) before the age of 5 years and followed up for 10 years. This work aims to study the vesico-sphincteric sequelae of this malformation. 38 patients showed early urinary incontinence post-operatively. Of them, 20 were re-evaluated 10 years later by pelvic ultrasonography, pressure flow studies combined with EMG and assessment of renal function. 8 patients refused to undergo these investigations and 10 were lost to follow-up. Of the 28 evaluable patients, 22 are currently continent and a complete urodynamic study was performed for the 6 (10%) incontinent patients. Of them, 3 showed uninhibited detrusor contractions. The vesical compliance was frequently within the normal limits. No case of detrusor-sphincteric dyssynergy or urethral hypotony was found. 2 were successfully treated by oxybutinin and biofeedback reeducation, 2 were partially improved but their prostates are still in growth and the possibility of implanting an artificial sphincter was discussed in the remaining 2. The urodynamic evaluation of those patients in the long-term is encouraging.     

Occupational lead exposure and hearing loss

Studies of adults, children, and laboratory animals suggest an association between lead exposure and hearing loss. A causal relationship might direct mandated medical surveillance of lead-exposed workers to include audiometric testing. A cross-sectional, computerized dataset was obtained from a private occupational health screening company to examine the relationship between blood lead level and hearing loss. Audiometry and blood lead results were available for 183 workers. A statistically significant correlation was found between blood lead level and an elevated hearing threshold at 400 Hz (P = 0.03); no other frequencies showed such a correlation. This finding suggests either an interaction between nose exposure and lead, interaction of other exposure factors (such as cigarette smoking), or that factors other than biomechanical ones render the organ of Corti more susceptible at 4000 Hz. Further evaluation of these questions should be undertaken. Computerized databases created for worker surveillance may be a source for data useful for examining other causal connections in occupational settings.     

Environmental urban lead exposure and blood lead levels in children of Mexico City

Lead contamination is now a leading public health problem in Mexico. However, there are few data on the lead content of various environmental sources, and little is known about the contribution of these sources to the total lead exposure in the population of children residing in Mexico City. We conducted a cross-sectional study in a random sample of 200 children younger than 5 years of age who lived in one of two areas of Mexico City. Environmental samples of floor, window, and street dust, paint, soil, water, and glazed ceramics were obtained from the participants' households, as well as blood samples and dirt from the hands of the children. Blood lead levels ranged from 1 to 31 micrograms/dl with a mean of 9.9 micrograms/dl (SD 5.8 micrograms/dl). Forty-four percent of the children 18 months of age or older had blood lead levels exceeding 10 micrograms/dl. The lead content of environmental samples was low, except in glazed ceramic. The major predictors of blood lead levels were the lead content of the glazed ceramics used to prepare children's food, exposure to airborne lead due to vehicular emission, and the lead content of the dirt from the children's hands. We conclude that the major sources of lead exposure in Mexico City could be controlled by adequate public health programs to reinforce the use of unleaded gasoline and to encourage production and use of unleaded cookware instead of lead-glazed ceramics.     

Survey of lead exposure around a closed lead smelter

OBJECTIVE: To test the hypothesis that elevated lead in soil is positively correlated with blood lead (BPb) levels in children in an urban population surrounding a closed lead smelter, a US Environmental Protection Agency Superfund clean-up site was surveyed. METHOD: A total of 827 volunteers including 490 children under 6 years of age participated. A questionnaire was administered. Blood lead was determined as was lead content of samples of house dust, soil, paint, and water of the participants' homes. RESULTS: The arithmetic mean venous BPb in 490 children between 6 and 72 months of age was 6.9 micrograms/dL (0.33 mumol/L) range 0.7 to 40.2 micrograms/dL (0.03 to 1.94 mumol/L). The BPb of 78 (16%) children in this group was > or = 10 micrograms/dL (0.48 mumol/L). Based on multiple regression modeling, lead in house dust accounted for 18% of the variance in BPb. Lead in paint together with the condition of the house were the main contributors to the dust lead variance (26%) with soil lead accounting for an additional 6%. Lead in paint alone accounted for 3% of the BPb variance. Lead in paint together with the condition of the house accounted for 12% of BPb variance, and lead in soil accounted for an additional 3%. Factors other than environmental lead such as education of parents, household income, and behavior were associated with BPb levels. CONCLUSIONS: The mean BPb in children was below the present level of concern of the Centers for Disease Control and Prevention. Children with BPb of > or = 10 micrograms/L (0.48 mumol/L) tended to live in poorly maintained older houses. Based on these findings lead in soil and paint in well-maintained homes contributed little to the lead exposure of children.     

Brain cancer and occupational exposure to lead

A recent report in the literature suggested a link between occupational exposure to lead and brain cancer. To explore the hypothesis, we applied a job-exposure matrix for lead to the occupation and industry codes given on the death certificate of 27,060 brain cancer cases and 108,240 controls who died of non-malignant diseases in 24 US states in 1984-1992. Brain cancer risk increased by probability of exposure to lead among Caucasian men and women with high-level exposure, with a significant twofold excess among Caucasian men with high probability and high level of exposure to lead (odds ratio = 2.1; 95% confidence interval, 1.1-4.0). Risks were also elevated in the low- and medium-probability cells for African-American men with high-level exposure to lead. Trend by intensity level was statistically significant among African-American men (all probabilities combined). Although exposure assessment was based solely on the occupation and industry reported on the death certificate, these results add to other epidemiologic and experimental findings in lending some support to the hypothesis of an association between occupational exposure to lead and brain cancer risk. Analytic studies are warranted to further test this hypothesis.     

Chronic exposure to environmental lead in Chilean infants

BACKGROUND: In Chile, there are several sources of environmental lead exposure. However, the few studies about lead levels in Chilean infants, do not allow to establish the prevalence of high lead levels in this population. AIM: To measure blood lead levels in nursing infants, living in rural and urban areas, from birth until two years of age. SUBJECTS AND METHODS: Newborns from public maternity hospitals in Santiago and a rural area were selected for the study. An umbilical cord blood sample was obtained at birth and venous blood samples thereafter, every 6 months until the age of 24 months. Lead levels were measured by atomic absorption spectrophotometry. Atmospheric lead was measured simultaneously every week in Santiago and the rural area. RESULTS: Three hundred twelve children from Santiago and 113 from the rural area completed the 24 months follow-up. The mean lead exposure for infants living in Santiago and in the rural area was 1.23 +/- 0.66 and 0.19 +/- 0.15 micrograms/m3 respectively (p < 0.001). Mean blood levels were always higher in infants from Santiago, compared to those from the rural area. At 24 months, 4.5% of children from Santiago and 0.7% of children from the rural area had blood lead levels over 10 micrograms/dl. Significant risk factors for high lead levels were recent painting of the house where the infant lives, eating soil, biting banisters and familiar labor exposure to lead. CONCLUSIONS: Infants living in an urban area and exposed to increased atmospheric lead levels have higher blood lead levels than infants living in a rural area.     

Nephron target sites in chronic exposure to lead

With established urinary markers of kidney integrity the early renal effects of lead have previously been considered to be mainly tubular or tubulointerstitial. In a cross-sectional study on 81 male lead-exposed workers and 45 age-matched controls (median blood lead concentrations 2.03 and 0.34 mumol/l respectively) not only well-established but also new urinary markers of renal integrity preferentially or exclusively located along the different nephron segments were analysed. Markers related to the glomerulus were 6-keto-prostaglandin 1 alpha, thromboxane B2, mainly produced in the glomerulus, and the extracellular matrix protein fibronectin. Markers of the proximal tubule were the brush-border antigens BBA, BB50, and HF5 and the intestinal alkaline phosphatase. Prostaglandin E2 and F2 alpha, preferentially synthesized in the collecting duct and medullary interstitial cells, served as markers of these more distal nephron segments. In contrast to previous studies on the early phase of lead nephrotoxicity, not only tubular but also glomerular involvement could be shown in the study presented here by increases in the median values of 6-keto-prostaglandin 1 alpha and decreases in fibronectin. The proximal tubular markers intestinal alkaline phosphatase and BBA confirmed that this particular segment of the nephron is affected by lead. Effects on the collecting tubule or medullary interstitial cells could also be observed. It is concluded that lead affects both the glomerulus and the tubular apparatus and that combinations of new and established markers could be valuable for a better definition and early detection of lead nephropathy.     

Assessment of lead exposure in schoolchildren from Jakarta

Children attending schools in urban areas with high traffic density are a high risk group for lead poisoning. We assessed the magnitude of lead exposure in schoolchildren from Jakarta by analyzing blood lead concentrations and biomarkers of heme biosynthesis. A total of 131 children from four public elementary schools in Jakarta (two in the southern district and two in the central district) were enrolled in the study. To evaluate lead pollution in each area, soil samples and tap water were collected. The mean blood lead concentration was higher in the central district than in the southern district (8.3 +/- 2.8 vs. 6.9 +/- 3.5 microg/100 ml; p<0.05); 26.7% of the children had lead levels greater than 10 microg/100 ml. In 24% of the children, zinc protoporphyrin concentrations were over 70 micromol/mol hemoglobin; in 17% of the samples, hemoglobin was less than 11 g/100 ml. All other values were within the physiological range. Blood lead concentration and hematological biomarkers were not correlated. Analyses of tap water revealed lead values under 0. 01 mg/l; lead contamination of soil ranged from 77 to 223 ppm. Our data indicate that Indonesian children living in urban areas are at increased risk for blood lead levels above the actual acceptable limit. Activities to reduce pollution (e.g., reduction of lead in gasoline) and continuous monitoring of lead exposure are strongly recommended.     

Renal effects of environmental and occupational lead exposure

Environmental and industrial lead exposures continue to pose major public health problems in children and in adults. Acute exposure to high concentrations of lead can result in proximal tubular damage with characteristic histologic features and manifested by glycosuria and aminoaciduria. Chronic occupational exposure to lead, or consumption of illicit alcohol adulterated with lead, has also been linked to a high incidence of renal dysfunction, which is characterized by glomerular and tubulointerstitial changes resulting in chronic renal failure, hypertension, hyperuricemia, and gout. A high incidence of nephropathy was reported during the early part of this century from Queensland, Australia, in persons with a history of childhood lead poisoning. No such sequela has been found in studies of three cohorts of lead-poisoned children from the United States. Studies in individuals with low-level lead exposure have shown a correlation between blood lead levels and serum creatinine or creatinine clearance. Chronic low-level exposure to lead is also associated with increased urinary excretion of low molecular weight proteins and lysosomal enzymes. The relationship between renal dysfunction detected by these sensitive tests and the future development of chronic renal disease remains uncertain. Epidemiologic studies have shown an association between blood lead levels and blood pressure, and hypertension is a cardinal feature of lead nephropathy. Evidence for increased body lead burden is a prerequisite for the diagnosis of lead nephropathy. Blood lead levels are a poor indicator of body lead burden and reflect recent exposure. The EDTA lead mobilization test has been used extensively in the past to assess body lead burden. It is now replaced by the less invasive in vivo X-ray fluorescence for determination of bone lead content.     

Menopause, menstrual and reproductive history, and bone density in northern Italy

A scheme for purification of hyaluronidase from Staphylococcus aureus 0-15 that allows to produce a 550-fold-purified preparation with a high specific activity was developed. Hyaluronidase was found to consist of two molecular forms with different molecular weights. Staphylococcus hyaluronidase referred to as a complex preparation and its molecular forms have action optimum at pH 5.0-7.2 and at a temperature between 30 and 37 degrees C. The enzymes were highly specific to their substrate: they catalyzed the depolimerization of hyaluronic acid but did not split the other glycosaminoglycans.     

Effects of lead exposure on licking and yawning behaviour in rats

Most studies on facial trauma in the pediatric age group focus on special subgroups. This investigation encompasses all traumatic facial injuries, minor and major, of children and adolescents. Epidemiological data of the type and pattern of injury of trauma patients less than 19 years of age, treated during a 3-year-period in a large metropolitan trauma centre were reevaluated. Of the 1385 patients, 68% had soft tissue injuries, 24% had dental trauma, and 8% fractures of facial bones. More than 90% suffered from minimal or minor trauma. The leading cause of injury was a fall, predominantly at the toddler stage. In adolescents an adult mechanism of trauma prevailed: over 60% of injuries were sequelae of an assault or altercation. The male sex predominated through all age groups and for all types of injuries. The bulk of soft tissue injuries are located within a small falling zone, extending from the nose to the mental area. There was a rising incidence of fractures of facial bones towards older age groups, mandibular fractures being the most common. Condylar fractures, with their potential impact on further growth of the mandible, are seen frequently in children and adolescents, making up 80% of the fractures of the lower jaw.     

A study of airborne Ulmaceae pollen in Modena (northern Italy)

We examined Ulmaceae airborne pollen at the Modena-Geophysical Observatory monitoring station in 1993. The pollen trap was placed 15 m above the ground. 365 daily slides were fully analyzed to obtain daily and bi-hourly pollen concentrations. Morphological analysis on native and introduced Ulmaceae pollen was also conducted between February 3rd and May 17th. Five pollen types were identified: Celtis cf. australis, Ulmus glabra, Ulmus cf. laevis, Ulmus cf. minor, and Ulmus minor/laevis. Pollen concentrations and percentages showed that the Elm family contributed little pollen to the air (about 1% of the total pollen recorded), Ulmus and Celtis being 0.9% and 0.04%, respectively. The maximum levels were 30 p/m3/24 hr and 118 p/m3/ 2 hr (Ulmus) and 4 p/m3/24 hr and 13 p/m3/2 hr (Celtis). The highest levels of Ulmus were during the morning and afternoon, while the afternoon was highest for Celtis. In general, Ulmaceae trees appear worth planting in urban areas, but Celtis pollen should also be monitored at human height.     

Increased prevalence of hypertension and long-term arsenic exposure

A possible role of endothelin (ET)-1 in mediating hypoxic pulmonary vasoconstriction (HPV) was examined by comparing haemodynamic differences between ET-1-induced vasoconstriction and HPV in isolated perfused rat lungs. An ETA receptor antagonist (BQ123) was also employed to assess the effects of ET-1. The pulmonary arterial pressure (Ppa) was significantly increased by alveolar hypoxia (3% O2) and by ET-1 (5 nM). The pulmonary microvascular pressure was not changed by hypoxia, but increased more than two-fold by ET-1 (P < 0.01). Hypoxia significantly increased pulmonary arterial resistance (P < 0.01) while ET-1 significantly increased pulmonary venous resistance (P < 0.01), and slightly increased arterial resistance. Lung weight was increased by ET-1 and decreased by hypoxia, accompanied by similar Ppa responses in both cases. BQ123 (10(-6) M and 10(-5) M) did not influence the changes in Ppa and lung weight induced by hypoxia or angiotensin II (0.3 micrograms). BQ123 did, however, suppress (P < 0.05) the increase in Ppa and lung weight induced by 5 nM ET-1. Thus, it appears unlikely that ET-1 is involved in changes in pulmonary vascular tone during acute HPV.     

Improvement in semen quality associated with decreasing occupational lead exposure

BACKGROUND: Cross-sectional studies have suggested that occupational lead exposure may adversely affect sperm quality. METHODS: Sperm quality changes were prospectively assessed in 19 men employed at a car battery plant where efforts were made to decrease the exposure level. The participants delivered monthly samples of semen and venous blood during their employment at the factory. The factory then closed, and additional samples were obtained from 16 of the men. RESULTS: Average blood-lead concentrations decreased from 2.03 mumol/l to 0.96 mumol/l during the observation period. Concomitantly, significant improvements were seen in the proportion of motile cells both at sample delivery and after 24 hr, and in penetration. However, the sperm cell concentration and the proportion of morphological abnormalities did not change. CONCLUSIONS: These results support the notion that occupational lead exposure at currently acceptable levels has a small adverse effect on sperm quality, especially sperm motility, and that this effect is at least partially reversible.     

Brain stimulation reward following chronic lead exposure in rats.

Adult male rats were exposed to drinking water containing either 500 parts per million (ppm) lead acetate or an equal concentration of sodium acetate for 80 days. Bipolar electrodes were then implanted into the medial forebrain bundle (MFB), and rats were allowed to recover for 7 days. On Day 8 postsurgery, control and lead-treated rats were placed in an operant chamber and shaped to press a lever to receive 200-msec trains of current. Data from a range of current intensities and frequencies were recorded to obtain threshold values for each rat, defined as the stimulation needed to support half-maximal lever responding. Results indicated that chronic lead exposure attenuated the reinforcing effect of brain stimulation. Because of the large number of reward systems mediated by the MFB nucleus accumbens pathway, these data suggest that a variety of motivational phenomena may be affected by contaminant exposure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)