Non-occupational lead exposure and hypertension in northern Italy

BACKGROUND: Previous research has addressed the issue that low-level blood lead concentration could be associated with an increased risk of hypertension. METHODS: This paper examines the cross-sectional association between blood lead and hypertension in 630 adult males not employed in activities characterized by specific exposure to lead and living in two Northern Italian cities (Verona and Brescia). The participants, aged 26-69 years, constituted a random sample of the patients in the practice of a general practitioner (Verona) and of regular blood donors (Brescia). Logistic regression analysis was used to evaluate the effects of selected variables (blood lead, blood cadmium, zinc erythroprotoporphyrin, haemoglobin, whole blood viscosity, age, body mass index, smoking habits and alcohol consumption) on the probability of being hypertensive. RESULTS: The blood lead concentration (range: 4.3-46.9 micrograms/dl; median: 14.8 micrograms/dl) was very similar in the two samples, whereas the prevalence of hypertension was significantly higher in the Verona sample than in the Brescia sample (20.4% versus 8.3%). Hypertensive subjects showed significantly higher blood lead levels than normotensive ones. In a preliminary (univariate) analysis blood lead levels, body mass index (BMI) and age were each significantly related to the prevalence of hypertension. After adjusting for age and/or BMI, statistical significance of the relationship between blood lead and hypertension was lost.CONCLUSIONS. The present study showed that blood lead is weakly related to hypertension in non-occupationally exposed men. The statistical significance of this association disappeared when age and BMI were used to make adjustments.     

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.     

Age-related macular disease in rural southern Italy

OBJECTIVE: To report the prevalence of age-related maculopathy (ARM) in Salandra, a small, isolated southern Italian community, to test the hypothesis that an environmental factor, scarce in such a remote community but ubiquitous in modern industrial societies, might modify the risk of developing ARM. DESIGN: Population-based cross-sectional survey. MAIN OUTCOME MEASURES: Prevalence of advanced age-related macular degeneration (ARMD) (geographic atrophy or exudative maculopathy) and ARM (large, soft drusen or retinal pigment epithelium changes, or both) defined by fundus biomicroscopy and 30 degrees stereoscopic, macular photography. Self-sustenance was assessed by interview of participants and local shop retailers. The degree of genetic isolation was computed using a model that fits the genetic population structure with the frequency distribution of surnames in the community. RESULTS: A full ophthalmic examination was undertaken in 366 (63.5%) of 576 eligible participants, 354 (96.7%) of whom had clinical or photographic assessment for the presence of ARMD and 310 (84.6%) of whom had drusen characteristics graded on color transparencies for ARM. The overall prevalence of ARMD was 1.1%. Drusen larger than 50 microns and more numerous than 10 were found in 4.5% of subjects. Salandra was the birthplace of 87.2% of participants and for 77.3% of both parents of each subject. People in the community tended to consume homegrown products. CONCLUSION: The prevalence of ARM may be lower in this self-sustained farming community than elsewhere in the industrialized world.     

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.     

Maternal and neonatal outcomes after prolonged latent phase

Glycol ethers such as 2-ethoxyethanol (EE) are widely used as solvents because they are miscible in aqueous and organic solutions. Toxic effects of EE in rodents include teratogenicity, fetotoxicity, hematotoxicity, and testicular atrophy. The purpose of this study was to determine the effect of dose on the absorption, metabolism, and excretion of 2-ethoxy [U-14C]ethanol by F344/N rats after inhalation exposure. Rats were exposed to either 5 ppm EE for 5 hr 40 min or 46 ppm EE for 6 hr. The uptake and metabolism of EE were linear in the concentration range studied. Significant percentages of the retained doses were exhaled during (22%) and after exposure (16%) as 14CO2. Forty-six percent of the retained dose was excreted in the urine. Approximately 10% of the retained dose was detected in the carcass 66 hr after exposure. The major urinary metabolite was ethoxyacetic acid (EAA), the toxic metabolite of EE. The amount of EAA excreted was linearly related to exposure concentration. Ethylene glycol and N-ethoxyacetyl glycinate were identified as minor metabolites excreted in the urine. The results of this study suggest that the toxicity of inhaled EE should be directly proportional to the exposure concentration up to 46 ppm if the toxicity of EE is due to EAA.     

Maternal and neonatal outcome following prolonged labor induction

Early diagnosis of invasive group A beta streptococcal (GABS) infection has been achieved in a patient using magnetic resonance imaging (MRI) complemented by needle aspiration. Life-saving treatments of GABS infection that include immediate surgical debridement along with the administration of i.v. antibiotics, gamma globulin, and hyperbaric oxygen were then implemented successfully to prevent the development of streptococcal toxic shock syndrome. While MRI is valuable in making early diagnosis of GABS, it should not delay surgical intervention.     

Phage types and ribotypes of Salmonella enteritidis in southern Italy

Differently from other European countries, Southern Italy was affected by a considerable increase in human infections due to Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) only after 1990. On the present investigation, two groups of S. Enteritidis strains isolated during the low-incidence period 1980-1984 and the epidemic period 1990-1993, respectively, have been submitted to phage-typing and ribotyping in order to ascertain whether the epidemic increase was determined by the spread of a foreign bacterial clone or not. Among the 150 isolates relative to the aforesaid two periods, 12 different phage types (PTs) were observed. PT4 was the most common phage type among the strains isolated in 1980-1984 (61%) as well as in those of the epidemic period 1990-1993 (72%). PT8 was the second most frequent (33%) phage type in 1980-1984. It was substituted by PT1 (19%) in the 1990-1993 period. Analysis of rDNA patterns obtained after Hinc II digestions and Escherichia coli rRNA hybridizations showed 8 different patterns, A to H. The great majority of the strains studied (140 isolates, 93%) belonged to the ribotype A, showing a similar frequency both in 1980-1984 (36 of 39, 92%) and in 19901993 (104 of 111, 94%). The predominance of PT4 and ribotype A among both preepidemic and epidemic strains is in agreement with the hypothesis that host genetic diversity decline and modern farming practices in the poultry industry have facilitated a widespread dissemination of preexisting endemic strains. This hypothesis urges to plan new strategies in preventing S. Enteritidis infections.     

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.     

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.     

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.     

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.     

Maternal attitude toward pregnancy and the risk of neonatal death

OBJECTIVES: Reduced options for fertility control over the past decade have increased the rates of unwanted pregnancy. We evaluated whether a woman's negative attitude toward her pregnancy increased the risk of perinatal mortality, in a large, prospective cohort study. METHODS: The association between attitude toward the pregnancy and perinatal mortality was evaluated in a longitudinal cohort study of 8823 married, pregnant patients enrolled from 1959 to 1966 in the Child Health and Development Studies. RESULTS: Women who reported during the first trimester of prenatal care that the pregnancy was unwanted were more than two times more likely to deliver infants who died within the first 28 days of life than were women reporting accepted pregnancies. A positive attitude toward pregnancy was not associated with fetal death or post-neonatal death. CONCLUSIONS: These data, collected when induced abortions were illegal, may have important implications for the 1990s. If maternal attitude toward the pregnancy is associated with neonatal mortality and abortion laws change such that access is restricted, infant mortality may increase because a greater proportion of births will be unwanted.