Biomedical subjects

E Palazuelos

Publications and source records attributed to E Palazuelos.

12 recordsLinked to original sources

PubMed1997

Higher milk intake during pregnancy is associated with lower maternal and umbilical cord lead levels in postpartum women.

Lead exposure and its deleterious effects continue to be a problem in many countries. The lack of effective and safe treatments for low-level intoxication has promoted environmental interventions to control different sources of lead. In this study we evaluated the effect of milk consumption in 1849 mother-and-child pairs participating in the lead surveillance program in Mexico City. The mean lead levels were 11.2 micrograms/dL for maternal blood lead (MBL) and 10.8 micrograms/dL in umbilical cord. The correlation between blood lead and umbilical cord lead was r = 0.74. Forty-eight percent of the MBL exceeded 10 micrograms/dL and 9.5% exceeded 20 micrograms/dL. Maternal blood lead was positively related to the use of lead-glazed ceramic were and to traffic exposure and was inversely related to the consumption of milk and orange juice. Women who reported the consumption of more than 7 glasses of milk per week had a blood lead level of 8.7 micrograms/dL; in comparison, those women who reported a consumption of less than 7 glasses per week had a blood lead level of 11.1 micrograms/dL. Similar findings were observed for lead measured in umbilical cord. The association between lead levels and milk intake remained unchanged after taking in consideration other predictors of blood lead. This study suggests that a simple intervention could reduce lead burden among women and their newborns.

Animals↗

PubMed1997

Decrease in birth weight in relation to maternal bone-lead burden.

OBJECTIVES: Birth weight predicts infant survival, growth, and development. Previous research suggests that low levels of fetal lead exposure, as estimated by umbilical cord blood-lead levels at birth, may have an adverse effect on birth weight. This report examines the relationship of lead levels in cord blood and maternal bone to birth weight. METHODS: Umbilical cord and maternal venous blood samples and anthropometric and sociodemographic data were obtained at delivery and 1-month postpartum. Blood-lead levels were analyzed by atomic absorption spectrophotometry. Maternal tibia and patella lead levels were determined at 1-month postpartum with use of a spot-source 109Cd K-X-ray fluorescence instrument. The relationship between birth weight and lead burden was evaluated by multiple regression with control of known determinants of size at birth. RESULTS: Data on all variables of interest were obtained for 272 mother-infant pairs. After adjustment for other determinants of birth weight, tibia lead was the only lead biomarker clearly related to birth weight. The decline in birth weight associated to increments in tibia lead was nonlinear and accelerated at the highest tibia lead quartile. In the upper quartile, neonates were on average, 156 grams lighter than those in the lowest quartile. Other significant birth weight predictors included maternal nutritional status, parity, education, gestational age, and smoking during pregnancy. CONCLUSIONS: Our results indicate that bone-lead burden is inversely related to birth weight. Taken together with other research indicating that lead can mobilize from bone into plasma without detectable changes in whole blood lead, these findings suggest that bone lead might be a better biomarker than blood lead. Because lead remains in bone for years to decades, mobilization of bone lead during pregnancy may pose a significant fetal exposure with health consequences, long after maternal external lead exposure has declined.

Birth Weight↗

PubMed1996

Dietary and environmental determinants of blood and bone lead levels in lactating postpartum women living in Mexico City.

Despite the recent declines in environmental lead exposure in the United States and Mexico, the potential for delayed toxicity from bone lead stores remains a significant public health concern. Some evidence indicates that mobilization of lead from bone may be markedly enhanced during the increased bone turnover of pregnancy and lactation, resulting in lead exposure to the fetus and the breast-fed infant. We conducted a cross-sectional investigation of the interrelationships between environmental, dietary, and lifestyle histories, blood lead levels, and bone lead levels among 98 recently postpartum women living in Mexico City. Lead levels in the patella (representing trabecular bone) and tibia (representing cortical bone) were measured by K X-ray fluorescence (KXRF). Multivariate linear regression models showed that significant predictors of higher blood lead included a history of preparing or storing food in lead-glazed ceramic ware, lower milk consumption, and higher levels of lead in patella bone. A 34 micrograms/g increase in patella lead (from the medians of the lowest to the highest quartiles) was associated with an increase in blood lead of 2.4 micrograms/dl. Given the measurement error associated with KXRF and the extrapolation of lead burden from a single bone site, this contribution probably represents an underestimate of the influence of trabecular bone on blood lead. Significant predictors of bone lead in multivariate models included years living in Mexico City, lower consumption of high calcium content foods, and nonuse of calcium supplements for the patella and years living in Mexico City, older age, and lower calcium intake for tibia bone. Low consumption of milk and cheese, as compared to the highest consumption category (every day), was associated with an increase in tibia bone lead of 9.7 micrograms Pb/g bone mineral. The findings of this cross-sectional study suggest that patella bone is a significant contributor to blood lead during lactation and that consumption of high calcium content foods may protect against the accumulation of lead in bone.

Adolescent↗

PubMed1995

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.

Adult↗

PubMed1994

Acute high-dose lead exposure from beverage contaminated by traditional Mexican pottery.

Screening and follow-up blood lead measurements in a 7-year-old child of a US Embassy official in Mexico City revealed an increase in blood lead concentration from 1.10 to 4.60 mumol/L in less than 4 weeks. The cause was traced to fruit punch contaminated with lead leached from traditional ceramic pottery urns. Consumption of the contaminated punch at a picnic was associated with a 20% increase in blood lead concentrations among embassy staff and dependants who were tested 6 weeks after the exposure. This episode highlights the continued health risk, even from brief exposure, posed by traditional pottery in Mexico.

Ceramics↗

PubMed1994

Sources of lead exposure in Mexico City.

Many countries, including Mexico, are facing a largely unrecognized epidemic of low-level lead poisoning. Mexico is the sixth largest lead-producing country in the world, and 40% of its production is used locally in different industrial processes that cause lead contamination of the environment. The major sources and pathways of lead exposure among the Mexican population are gasoline emissions, lead-glazed ceramics, leaded paint, and lead in canned foods and beverages. In this paper we present evidence for the presence of lead in different environmental media and its impact on blood lead levels of the Mexican population. Although during the last few years important measures have been implemented to decrease lead exposure, our findings suggest that lead poisoning is still an important problem in Mexico. There is an urgent need for regulatory policies that implement stricter control to protect the Mexican population. There is also a need to develop adequate programs to reduce the lead burden and the associated health effects in the population that has been chronically exposed.

Ceramics↗

PubMed1991

Lead-glazed ceramics as major determinants of blood lead levels in Mexican women.

The aim of this study was to determine the main contributors to blood lead levels in a population of women from middle to low socioeconomic status in the southwestern part of Mexico City. Within this area, the authors selected a random sample of 200 women. Age ranged from 21 to 57 years, with a mean of 36 years. Among 99 women who agreed to participate in this study, blood lead levels ranged from 1 to 52 micrograms/dL, with a mean of 10.6 micrograms/dL. Five percent of the women had a blood lead level over 25 micrograms/dL and 22% over 15 micrograms/dL. There was no significant trend in blood levels according to age. The main determinants of blood lead levels were higher socioeconomic status (presence of telephone in the house, t-test, p = 0.01) and using lead-glazed ceramics (LGC) to prepare food (t-test, p less than 0.005). There was a significant increasing trend in blood lead levels with increasing frequency of consumption of food prepared in LGC (test for trend, p = 0.0008). Among the dishes prepared in LGC, the main determinant was the consumption of stew. Time spent outdoors and consumption of tap water and of canned food were not important determinants of blood lead levels. The population attributable risk of high blood level (less than 15 micrograms/dL) due to the use of LGC was 58%. These findings demonstrate the major role of traditional pottery as a contributor to blood lead levels in this population and emphasize the need for interventions to produce lead-free pottery.

Adult↗

PubMedDate not supplied

Vehicular traffic as a determinant of blood-lead levels in children: a pilot study in Mexico City.

The major determinants of blood-lead levels were studied in 90 children who attended an outpatient pediatric clinic in Mexico City. All children, who were from 1-10 y of age, were from homes for which socioeconomic status had been categorized as medium to high. Blood-lead levels ranged from 0.17 (standard deviation [SD] = 0.008) to 1.21 (SD = 0.06 mumol/l). The main determinant of blood-lead levels was place of residence. Children who lived on private streets (i.e., low-traffic areas) had a significantly lower blood-lead level than children who lived on large avenues and who resided close to main roads (p = .0001, r2 = .27). This observation documented high exposure levels among children who live in Mexico City and suggested that leaded fuel used in Mexico could play an important role in determining blood-lead levels in this population.

Automobile Driving↗

PubMedDate not supplied

Blood lead level and neurobehavioral development among children living in Mexico City.

This cross-sectional study examined the association between blood lead levels and neuropsychological and behavioral development of 139 children (7-9 y of age) who attended school in the southwestern part of Mexico City. A trained psychologist administered an IQ test to 84% of the children, and teachers graded them for agility, socialization, expression, and knowledge. Parents also answered a questionnaire on demographic and socioeconomic variables. Anodic stripping voltametry was used to determine blood lead levels. Regression models were used to determine the best predictors of IQ and teachers' rating scores. The mean blood lead level was 19.4 micrograms/dl (standard deviation [SD] = 7.6), with a geometric mean of 17.8 micrograms/dl (95% confidence interval [95% CI] = 16.5-19.1). Blood lead was the strongest predictor of full-scale IQ, and there was a significant negative trend between blood lead, full-scale IQ, and teachers' rating scores. In this study, children with higher levels of blood lead performed more poorly on psychometric tests and had poorer educational attainment than their counterparts. These results suggest an association between neuropsychological and behavioral impairment and lead exposure.

Child↗

PubMedDate not supplied

Risk factors for high levels of lead in blood of schoolchildren in Mexico City.

Risk factors associated with blood lead levels exceeding 15 microg/dl were analyzed in this report. This relatively high lead level was selected because, at the time the study commenced, it was considered to be a "safe" level. A total of 1583 schoolchildren were studied. The students were from (a) two areas in Mexico City (Tlalnepantla and Xalostoc) that have had historically high concentrations of lead in air, and (b) three areas (Pedregal, Iztalpalapa, and Centro) with less impressive air lead levels. Parents were presented with a questionnaire that solicited information about lead risk factors. A bivariate analysis and a multilogistic analysis were conducted to identify associations and to identify the model that most accurately explains the variability of the sample. High blood lead concentrations were found in children who lived in Xalostoc and Tlalnepantla (16.1 and 17.0 microg/dl, respectively), and the lowest concentration (i.e., 10 microg/dl) was found in children from Iztapalapa. The strongest association was with area of residence, followed by education level of parents, cooking of meals in glazed pottery, and chewing or sucking of yellow or other colored pencils. A child's area of residence is the most significant risk factor that must be accounted for when any study of lead and blood lead concentrations is undertaken. Follow-up in similar populations should assist greatly in the evaluation of the impact of governmental actions on public health.

Air Pollutants↗

PubMedDate not supplied

High blood lead levels in ceramic folk art workers in Michoacan, Mexico.

Ceramic folk art workers are at risk for developing lead intoxication. These workers live in small settlements, which often lack sanitation services, and these individuals work with ceramics in their homes. The study population comprised individuals of all ages from three rural communities in central Michoacan (Tzintzuntzan, Tzintzunzita, and Colonia Lazaro Cardenas). A survey questionnaire, which was provided to each individual, included questions about household characteristics, presence of a clay oven in the home, and use of lead oxide ("greta") and other hazardous products. Venous blood samples were obtained from the workers. We found lead exposure to be reduced if the home floor was covered and if the house had been painted < or =1 y prior to study. Blood lead levels exceeded the maximum level permitted, but the levels were lower than those found in the 1970s, during which time study techniques for analyzing samples differed from those used in the present study. In addition, activity patterns of the populations differed during the two studies.

Adolescent↗

PubMedDate not supplied

[Environmental exposure factors and the concentrations of blood lead in Mexico City children].

Risk factors that contribute to high blood lead concentrations were determined in 113 infants, aged 3 to 7 years old, that attended pediatric consultation at the American British Cowdray Hospital (ABC) from May 1991 to October 1992. The range of blood lead concentrations was 4 to 45 micrograms/dl, with an average value of 15.6 micrograms/dl (DE = 7.0), and a geometric mean of 14.2 micrograms/dl (IC 95% = 11.9-16.5). Seventy six percent of the children presented blood lead concentrations of over 10 micrograms/dl. The main predictors of blood lead levels were the use of glazed pottery for cooking rice (ANOVA, p = 0.0000) and the storage of food in glazed pottery (t-test, p = 0.005). There was a significant association between the use of glazed pottery for cooking rice and blood lead concentrations (tendency p = 0.000). The attributable risk of this population due to the use of glazed pottery was 81 per cent. This study sustains the need to develop and enforce public health policies for programs of lead poisoning prevention.

Adolescent↗