Lead (II) detection and contamination routes in environmental sources, cookware and home-prepared foods from Zimatlán, Oaxaca, Mexico

Association between lead source exposure and blood lead levels in some lead manufacturing countries: A systematic review and meta-analysis

Lead is one of the 10 most toxic chemicals of greatest concern for its effects on public health. Predominantly, in undeveloped countries, high blood lead levels (BLLs) persist in the population. To develop intervention strategies that may reduce lead exposure in populations, it is a priority to know the sources of lead pollution. The objective of this critical review and meta-analysis is to assess whether there is an association between different sources of lead exposure and the mean difference in blood lead levels in people exposed. To identify the major lead source exposure, a statistical analysis was performed on selection studies. This investigation reveals the limited information available on the sources of lead in Mexico and other lead producer countries, such as Croatia, Ecuador, Brazil, South Korea, India, Nigeria, Turkey, and China. Meta-analysis could be performed only in battery, smelting mining, and glazed ceramic workers. Battery manufacturing workers have the highest mean difference level of lead in their blood worldwide. Mexico has the second highest mean difference BLL in battery workers in the world. An interesting difference between the mean difference in BLL in mining workers from uncontrolled industry (-39.38) and controlled industry (-5.68) was found. This difference highlighted the success of applying strict control of lead sources and community education to reduce BLL and its potential harmful effects on human health and the environment. Children living near mining sites have the highest mean difference BLL (-11.1). This analysis may aid in assessing the source of lead exposure associated with a range of BLLs in people. Furthermore, this review highlights several social and cultural patterns associated with lead exposure and lead levels in control populations. These results could help to develop international lead regulations and appropriate public health guidelines to protect people around the world.

Investigating aluminum cookpots as a source of lead exposure in Afghan refugee children resettled in the United States

BACKGROUND

Afghan refugee children resettled in Washington State have the highest prevalence of elevated blood lead levels (BLLs) of any other refugee or immigrant population. Resettled families brought several lead-containing items with them from Afghanistan, including aluminum cookpots.

OBJECTIVES

To evaluate the potential contribution of lead-containing cookpots to elevated BLLs in Afghan children and determine whether safer alternative cookware is available.

METHODS

We screened 40 aluminum cookpots for lead content using an X-ray fluorescence (XRF) analyzer and used a leachate method to estimate the amount of lead that migrates into food. We also tested five stainless steel cookpots to determine whether they would be safer alternatives.

RESULTS

Many aluminum cookpots contained lead in excess of 100 parts per million (ppm), with a highest detected concentration of 66,374 ppm. Many also leached sufficient lead under simulated cooking and storage conditions to exceed recommended dietary limits. One pressure cooker leached sufficient lead to exceed the childhood limit by 650-fold. In contrast, stainless steel cookpots leached much lower levels of lead.

SIGNIFICANCE

Aluminum cookpots used by refugee families are likely associated with elevated BLLs in local Afghan children. However, this investigation revealed that other U.S. residents, including adults and children, are also at risk of poisoning by lead and other toxic metals from some imported aluminum cookpots.

IMPACT STATEMENT

Some aluminum cookware brought from Afghanistan by resettled families as well as cookpots available for purchase in the United States represent a previously unrecognized source of lead exposure.

Decreased Anemia Prevalence Among Women and Children in Rural Baja California, Mexico: A 6-Year Comparative Study

Anemia is a public health problem in Mexico. This study sought to determine the prevalence and correlates of anemia among women and children residing in a rural farming region of Baja California, Mexico. An existing partnership between universities, non-governmental organizations, and an underserved Mexican community was utilized to perform cross-sectional data collection in 2004-2005 (Wave 1) and in 2011-2012 (Wave 2) among women (15-49 years) and their children (6-59 months). All participants completed a survey and underwent anemia testing. Blood smears were obtained to identify etiology. Nutrition education interventions and clinical health evaluations were offered between waves. Participants included 201 women and 99 children in Wave 1, and 146 women and 77 children in Wave 2. Prevalence of anemia significantly decreased from 42.3 to 23.3 % between Waves 1 and 2 in women (p < 0.001), from 46.5 to 30.2 % in children 24-59 months (p = 0.066), and from 71.4 to 45.8 % in children 6-23 months (p = 0.061). Among women in Wave 1, consumption of iron absorption enhancing foods (green vegetables and fruits high in vitamin C) was protective against anemia (p = 0.043). Women in Wave 2 who ate ≥4 servings of green, leafy vegetables per week were less likely to be anemic (p = 0.034). Microscopic examination of blood smears revealed microcytic, hypochromic red blood cells in 90 % of anemic children and 68.8 % of anemic women, consistent with iron deficiency anemia.

Environmental exposure to lead and mercury in Mexican children: a real health problem

Exposure to lead (Pb) and mercury (Hg) remains a world public health problem, particularly for young children in developing countries. In Mexico, the main sources of exposure to Pb and Hg are wastes from human activities that increase the natural sources of these metals. Pb and Hg are highly toxic during development and maturation periods of the central nervous system (CNS); these effects are associated with the risk for neurodegenerative diseases. Mexico has numerous exposure sources to Pb and Hg; nevertheless, information on exposure in children is limited, particularly for Hg. Therefore, we conducted a review of the studies performed in children exposed to Pb and Hg. Data presented support that an important proportion of Mexican children have Pb levels above values associated with dangerous effects. On the other hand, studies on Hg-exposure are scarce, so we need more studies to estimate the magnitude of the problem and to determine exposure levels in Mexican children. Available data support the urgent need for coordinated actions among researchers, and health and environmental government authorities to implement education and nutritional campaigns, as well as to decrease exposure and effects of Pb and Hg. In addition, there must be a priority for the implementation of educational campaigns directed to the general population, but with emphasis in parents, education staff and health care providers to decrease both the risk of exposure of children to Pb and Hg and the effects of the exposure to these metals.

Determination of arsenic leaching from glazed and non-glazed Turkish traditional earthenware

Glazed and non-glazed earthenware is traditionally and widely used in Turkey and most of the Mediterranean and the Middle East countries for cooking and conservation of foodstuff. Acid-leaching tests have been carried out to determine whether the use of glazed and non-glazed earthenware may constitute a human health hazard risk to the consumers. Earthenware was leached with 4% acetic acid and 1% citric acid solutions, and arsenic in the leachates was measured using hydride generation atomic absorption spectrometry. Arsenic concentrations in the leach solution of non-glazed potteries varied from 30.9 to 800 μg L⁻¹, while the glazed potteries varied generally from below the limit of detection (0.5 μg L⁻¹) to 30.6 μg L⁻¹, but in one poorly glazed series it reached to 110 μg L⁻¹. Therefore, the risk of arsenic poisoning by poorly glazed and non-glazed potteries is high enough to be of concern. It appears that this is the first study reporting arsenic release from earthenware into food.

Lead, cadmium and cobalt (Pb, Cd, and Co) leaching of glass-clay containers by pH effect of food

Recent studies have shown that handcrafted glass-clay containers are a health risk because they can be contaminated by heavy metals, which can be transferred to food, thus reaching the human body to potentially cause illness. Therefore, in the present work, we evaluate the leaching of lead, cadmium, and cobalt from glass-clay containers into two types of food: tomato sauce (salsa), and chickpea puree. The containers were obtained from four regions in the Mexican state of Hidalgo. Repetitive extractions from the containers were carried out to quantify the leaching of the heavy metals into the salsa, the chickpea puree, and acetic acid using the technique proposed by the USFDA. The results show that greater use of the containers leads to more leaching of heavy metals into both types of food and into the acetic acid, with the greatest metal extraction recorded for the Ixmiquilpan vessels. These results indicate that the metals present in the glass-clay containers leach into the food and that increased reuse increases the risk to the people who use them in food preparation.

The voltammetric behaviour of lead at a microband screen-printed carbon electrode and its determination in acetate leachates from glazed ceramic plates

Microband screen-printed carbon electrodes (μBSPCEs) without further modification have been investigated as disposable sensors for the measurement of lead in acetate leachates from ceramic glazed plates. Cyclic voltammetry was employed to elucidate the electrochemical behaviour of Pb(2+) at these electrodes in a variety of supporting electrolytes. The anodic peaks obtained on the reverse scans, showed that Pb had been deposited as a thin layer on the surface of the μBSPCE. The anodic peak of greatest magnitude was obtained in 0.1M pH 4.1 acetate buffer containing 13 mM Cl(-). The effect of chromium, copper, phosphate, sulphate and tin was examined and under the conditions employed, no significant change in current was found. The μBSPCEs were evaluated by carrying out lead determinations for acetate leachates from glazed ceramic plates. A highly decorated ornamental plate was found to leach 400 μg Pb(2+) (%CV=1.91%). A second plate, designed for dinnerware was found not to leach any detectable levels of Pb(2+). However, once fortified with 2.10 μg of Pb (equivalent to 100 ng/ml in the leachate), a mean recovery of 82.08% (%CV=4.07%) was obtained. The performance characteristics indicate that reliable data has been obtained for this application which could identify potentially toxic sources of lead.