Impact of Air Pollution by Lead on the Heme Biosynthetic Pathway in School-Age Children

Abstract

Blood-lead level (Pb-B), erythrocyte delta-aminolevulinic acid dehydratase (ALAD) activity, free erythrocyte porphyrin (FEP) concentration, delta-aminolevulinic acid concentration in urine (ALAU), hematocrit value, and hemoglobin concentration were compared for groups of children 10-13 years old from areas differently polluted by lead (rural area and lead smelter area). The biological responses of the children were also compared with those observed in adults similarly exposed to lead (Pb-B: 10-40 mug/100 ml). Compared with the rural children, children living less than 1 km from the smelter exhibited a significant increase of Pb-B and FEP, a significant inhibition of ALAD, and a slight positive correlation of ALAU with Pb-B; however, they showed no biological signs of anemia. In children living approximately 1.5 km from the smelter, there was still a significant increase of Pb-B and a concomitant inhibition of ALAD, but no change in FEP concentration. Comparison of the dose-response curves between Pb-B and FEP in adult males, adult females, and children indicates that the sensitivity to lead is in the order of children larger than or equal to women greater than men. Based on the FEP response, it is proposed that 25 mug Pb/100 ml blood be regarded as the maximum biologically allowable concentration of lead in blood of school-age children.

Age and sensitivity to lead toxicity: a review.

“…Roels et al recently studied a population of children that lived near a lead smelter. In this group there was a direct correlation between the elevation of FEP values and blood lead levels (22), a finding noted by others (23). They also noted that children exhibited higher FEP values for a given blood lead level than did adults, and concluded that children were at a greater risk for the lead effect on the heme biosynthetic pathway.…”

Chumbo e cádmio no sangue e estado nutricional de crianças, Bahia, Brasil

“…Mais de 16% das crianças apresentaram PbS superior a 3,36 umol/l (ou 70 ug/100 ml) que denota risco eminente à saúde, podendo demandar tratamento quelante imediato 8 . Em populações de crianças belgas de belgas de 10 a 13 anos de idade, residindo a menos de um quilômetro de uma fundição de chumbo, a média (X ± s) de PbS foi de 1,45 ± 0,04 umol/l e de 0,45 ±0,01 umol/l, para crianças de uma área rural, não poluída 19 . Em crianças holandesas de 2-3 anos de idade, residindo a menos de um quilô-metro de uma fundição de chumbo a média de PbS foi de 0,95 umol/1 27 .…”

Characterizing Golden Eagle Risk to Lead and Anticoagulant Rodenticide Exposure: A Review

“…The threshold for EP elevation appears to be somewhat lower (20-30 μg/dL) in women than in men (Roels and Lauwerys 1987;Roels et al 1975Roels et al , 1976Roels et al , 1979, regardless of whether exposure is primarily by inhalation (occupational) or oral (nonoccupational). These studies were controlled for possible confounding factors such as iron deficiency or age, both of which increase erythrocyte ZPP.…”

“…However, peak ZPP levels lag behind peak levels of PbB. The threshold for this effect in children is approximately 15 μg/dL (Hammond et al 1985;Piomelli et al 1982;Rabinowitz et al 1986;Roels and Lauwerys 1987;Roels et al 1976), and may be lower in the presence of iron deficiency (Mahaffey and Annest 1986;Marcus and Schwartz 1987). A study of 95 mother-infant pairs from…”

“…The effects of chronic-duration exposure to lead in humans and in animals have been relatively well-studied. In humans, exposure to lead has been associated with (only representative citations are included) cardiovascular effects Schwartz 1995;Staessen et al 1994), hematological effects (Chisolm et al 1985;Roels and Lauwerys 1987;Roels et al 1976), musculoskeletal effects (Holness and Nethercott 1988;Marino et al 1989;Pagliuca et al 1990), effects on teeth in children (Gemmel et al 2002;Moss et al 1999), renal effects (Kim et al 1996a;Muntner et al 2003), alterations in serum hormone levels (Gustafson et al 1989;López et al 2000;Singh et al 2000a), cataracts (Schaumberg et al 2004), alterations in electroretinograms (Cavalleri et al 1982;Otto and Fox 1993;Rothenberg et al 2002a), altered vitamin D metabolism (Rosen et al 1980), alterations in immunological parameters (Fischbein et al 1993;Karmaus et al 2005;Lutz et al 1999;Pinkerton et al 1998;Sata et al 1998;Sun et al 2003;Ündeger et al 1996), neurobehavioral effects in adults (Awad El Karim et al 1986;Baker et al 1979Baker et al , 1983Haenninen et al 1979;Holness and Nethercott 1988;Lucchini et al 2000;Matte et al 1989;Pagliuca et al 1990;Pollock and Ibels 1986;…”