Lead Toxicity: Current Concerns

Abstract

Over the 20-year period since the first issue of Environmental Health Perspectives was published, there has been considerable progress in the understanding of the potential toxicity of exposure to lead. Many of these advances have been reviewed in published symposia, conferences, and review papers in EHP. This brief review identifies major advances as well as a number of current concerns that present opportunities for prevention and intervention strategies. The major scientific advance has been the demonstration that blood lead (PbB) levels of 10-15 pLg/dL in newborn and very young infants result in cognitive and behavioral deficits. Further support for this observation is being obtained by prospective or longitudinal studies presently in progress. The mechanism(s) for the central nervous system effects of lead is unclear but involve lead interactions within calcium-mediated intracellular messenger systems and neurotransmission. Effects of lowlevel lead exposure on blood pressure, particularly in adult men, may be related to the effect oflead on calcium-mediated control of vascular smooth muscle contraction and on the renin-angiotensin system. Reproductive effects of lead have long been suspected, but low-level effects have not been well studied. Whether lead is a carcinogen or its association with renal adenocarcinoma is a consequence of cystic nephropathy is uncertain. Major risk factors for lead toxicity in children in the United States include nutrition, particularly deficiencies ofessential metals, calcium, iron, and zinc, and housing and socioeconomic status. A goal for the year 2000 is to reduce prevalence of blood lead levels exceeding 15 Ag/dL.

The Metallothionein-Null Phenotype Is Associated with Heightened Sensitivity to Lead Toxicity and an Inability to Form Inclusion Bodies

“…36 Chronic nephropathy from lead exposure often shows interstitial fibrosis and cystic hyperplasia in humans and animals. 2,9,37,38 Lead is also a renal carcinogen in animals 14,39 and possibly in humans. 1 The profound nephrotoxicity induced by lead is characterized by cellular inclusion bodies and renal tubular dysfunction.…”

Lead Exposure and Environmental Health

“…Several studies on rats and other rodents indicated that blood lead concentrations > 30-40 µg/dL were associated with impairment of spermatogenesis and reduced concentrations of androgens (Pandya et al, 2012;Anjum et al, 2015). However, other animal studies, mainly about histopathological, spermatozoal, and hormonal end points, indicated that certain species and strains were quite resistant to the reproductive toxicity of lead (Goyer, 1993). The human studies focused mainly on semen quality, endocrine function, and birth rates in occupationally exposed subjects, and showed that exposure to concentrations of inorganic lead > 40 µg/dL in blood impaired male reproductive function by reducing sperm count, volume, and density, or changing sperm motility and morfology (Pant et al, 2014;Telišman et al, 2007).…”

Niveles de plomo sanguíneo en madres y recién nacidos derechohabientes del Instituto Mexicano del Seguro Social

“…Joel Navarrete-Espinosa, M.C., M.A.H., (1) Luz Helena Sanín-Aguirre, M.C., M.S.P., Dr. en C., (2,3) Celia Escandón-Romero, M.S.P., (1) Guadalupe Benitez-Martínez, M.S.P., (1) Gustavo Olaiz-Fernández, M.C., (4) Mauricio Hernández-Avila, M.C., Ph.D. (3) (1) Subjefatura de Epidemiología, Jefatura …”

“…E n México, como en muchos otros países de Améri-ca, la exposición ambiental a plomo con el riesgo de efectos deletéreos sobre los sistemas hematopoyético, hepático, renal, reproductivo y gastrointestinal [1][2][3] permanece como una amenaza. Además, en la actualidad, se reconoce su relación con daños neurológicos en niños, expresados a través de retardo en su desarrollo psicomotor.…”

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Plomo en sangre materna y del recién nacido ARTÍCULO ORIGINAL

Niveles de plomo sanguíneo en madres y recién nacidos derechohabientes del Instituto Mexicano del Seguro SocialJoel Navarrete-Espinosa, M.C., M.A.H., (1) Luz Helena Sanín-Aguirre, M.C., M.S.P., Dr. en C., (2,3) Celia Escandón-Romero, M.S.P., (1) Guadalupe Benitez-Martínez, M.S.P., (1) Gustavo Olaiz-Fernández, M.C., (4) Mauricio Hernández-Avila, M.C., Ph.D. (3) (1) Subjefatura de Epidemiología, Jefatura

AbstractObjective. To establish the relation between maternal blood lead (MBL) and umbilical cord blood lead (CBL) levels during delivery, and to determine the major predictors for MBL in women covered by the Mexican Institute of Social Security (MISS), in Mexico City.

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