Environmental lead exposure and its relationship to traffic density among Senegalese children: a cross-sectional study.

Leaded-gasoline is probably the primary source of lead (Pb) exposure in Dakar (Senegal). The present cross-sectional study was undertaken to investigate the levels of Pb in Senegalese children and to present helpful data on the relationship between Pb levels and changes in biological markers of heme biosynthesis and oxidative stress. A total of 330 children, living since birth either in rural or urban areas (ie, Khombole (n = 162) and Dakar (n = 168), respectively) were included. During this cross-sectional study, the mean blood (B)-Pb level in all children was 7.32 +/- 5.33 microg/dL, and was influenced by the area of residence and gender. In rural children, 27 subjects (16.7%), 18 boys (19.6%) and nine girls (12.9%), had a B-Pb level > 10 microg Pb/dL, whereas 99 urban children (58.9%), respectively, 66 boys (71.8%) and 33 girls (43.4%), had alarmingly high B-Pb levels. Accordingly, urine delta-aminolevulinic acid levels were higher in children living in the urban area than in the rural areas (P < 0.001), and closely correlated with the B-Pb levels (P < 0.01). Moreover, glutathione peroxidase (GPx) activity, selenium (Se) level, glutathione reductase (GR) activity, and glutathione status were significantly influenced by area of residence and/or by gender. GPx activity and Se level were not only negatively correlated with B-Pb levels, but also positively correlated together (P < 0.01). Taken together, the present results allow us to conclude that urban children have higher B-Pb levels than rural children, and that of these children, boys have higher B-Pb levels than girls, leading thereby to alterations of heme biosynthesis and pro-oxidant/antioxidant balance. We also suggest that exposure to Pb and the Pb-induced adverse effects merits attention and that the development of preventive actions are of increasing importance in Senegal.

Environmental lead exposure and its relationship to traffic density among Senegalese children: a pilot study.

In Senegal, as in many developing countries, traffic density is increasing in urban areas; in Dakar more than 50% of vehicles use gasoline. Yet the extent and real magnitude of the problem has neither been recognized nor assessed in these countries. Systemic data assessment of lead pollution and people's exposure are not well known in Senegal. This study was also designed to determine the impregnation levels of the lead released by the exhaust of cars and the changes of some early biological markers in Senegalese children. Blood lead (BPb) levels showed that all the children enrolled were exposed. However, lead exposure levels (from 34.7 to 145.8 microg/L) were less important for children living in rural areas (60.9+/-18.3 microg/L) than for those living in urban areas (106.7+/-16.9 microg/L). These changes could be correlated to the difference in the automobile traffic between both these regions (P < 0.001). BPb mean levels found in boys were higher than those in girls (P < 0.05). Despite elevated BPb levels, all values for blood zinc protoporphyrin and urine delta-aminolevulinic acid were within physiological ranges. In addition, variations in some biological markers of oxidative stress and renal disorders were seen; however, they must be confirmed by a future epidemiological study.

[Contamination by aflatoxins of local peanut oils prepared in Senegal]. / Contamination par les aflatoxines des huiles d'arachide artisanales préparées au Sénégal.

Aflatoxins are mycotoxins produced by certain strains of fungus (Aspergillus) which develop in peanut seeds. Peanut oil and peanut meal are widely used in Senegal. The risk of intoxication is quite real. We determined aflatoxin contamination levels in peanut oil and food prepared by small scale production plants in the Kaolack and Diourbel regions of Senegal. High performance liquid chromatography (HPLC) of the different samples showed that 80% of them were contaminated. Aflatoxin B(1), B(2), G(1) and G(2) were detected. The pattern of contamination was similar for the two regions. Aflatoxin B(1) was prevalent and found in over 85% of the samples. The mean content of this mycotoxin (the most dangerous toxin) was about 40 ppb, a value which largely exceeds specifications for allowable levels.

[Mango leaves (Manguifera indica, Anacardiacea) used as biomarker of pollution by pp'Dichlorodiphenyltrichloroethane (pp'DDT)]. / Utilisation des feuilles de manguier (Manguifera indica, Anacardiacea) comme bioindicateur de pollution par le pp'Dichlorodiphényltri-Chloroéthane (pp'DDT).

Dichlorodiphenyltrichloroethane (DDT), organochlorine pesticide, byanother way cumulative pesticide is banned in mostdeveloped countries. Whatever, it is still used in many countries in the Third World. This work consist to check whether this chemical compound is still used in Senegal. The biomarker of pollution by this pesticide for this research was mango leaves (mango tree is widespread in Senegal) open to accumulate halogenated hydrocarbons. Leaves sample were taken in many sites in the centerline of Dakar-Thiès (Senegal), then analysed by gas chromatography. The results allowed to note the presence of DDT and its metabolites [(dichlorodiphenyltrichloroethylen (DDE), (dichlorodiphenyltrichloroethane (DDD)] in most of samples. The comparison of DDT content in relation to those of the principal metabolite allowed to make the difference according to sample sites, an old contamination of an utilisation more or less recent of this pesticide. From those results, we can conclude that DDT, typical pesticide by its big persistence is still used in some spherical zones in this country, in particular in farming gardening zones.

[Measurement and levels of aflatoxins in small-scale pressed peanut oil prepared in the Diourbel and Kaolack regions of Senegal]. / Recherche et dosage des aflatoxines dans l'huile de pression artisanale préparée dans les regions de Diourbel et Kaolack (Sénégal).

Aflatoxins are mycotoxins produced by some strains of fungus (Aspergillus) which develops in peanuts seeds. Peanuts oil and past are very used up in Senegal, then the aflatoxins poisoning risk are very actual. This study relates to the determination of contamination levels by aflatoxins from peanut oil food prepared by small scale production in areas of Kaolack and Diourbel. High Performance Liquid Chromatography (HPLC) analysis of the different samples showed that 80% of them were contaminated in the areas of Kaolack and Diourbel. Aflatoxin B1, B2, G1 and G2 has been detected with a profile of contamination almost identical in the both areas. Aflatoxin B1 was prevalent and has been found in over 85% of samples. Mean contents of this mycotoxin (the most dangerous toxin) is about 40 ppb, value widely superior to allowable specifications.

[Bacteriological study of purulent nasopharyngitis in children in Senegal]. / Etude bactériologique des rhinopharyngites purulentes de l'enfant au Sénégal.

BACKGROUND: S pneumoniae, H influenzae and M catarrhalis are the main bacteria isolated from rhinopharynx in Europe. The purpose of this work was to study the frequency of potential pathogenic bacteria isolated from acute purulent rhinopharyngitis among children in Senegal. POPULATION AND METHODS: Ninety-three children from one month to 7-years old suffering from purulent rhinopharyngitis were recruited from April 1 to July 1996. The withdrawal samples were taken from the cavum with a swab which was immediately immersed in an agar shipping medium. Bacteria's grouping and serotyping were made by immunoagglutination. A standard antibiogram was made for all isolates and furthermore the minimal inhibitory concentration (MIC) were determined for S pneumoniae. RESULTS: Two hundred bacterial strains were isolated: S pneumoniae 28% (60% of the children), C group streptococci: 19% (41% of the children), H influenzae: 15.5% (33% of the children), S pyogenes: 9.5% (20% of the children), S aureus: 8% (17% of the children) and M catarrhalis: 6% (13% of the children). The other isolates were: B and D groups streptococci, P aeruginosa and Klebsiella spp. S pnuemoniae strains belonged to serogroups 6, 19 and 23. Only three strains of H influenzae were capsulated (serotype b). Infants aged from 6 to 18 months were the most affected. No resistance to penicillin was observed for S pneumoniae and S pyogenes. Ampicillin (81%) and chloramphenicol (96%) both inhibited the majority of H influenzae strains. CONCLUSIONS: This descriptive bacterial epidemiology study of children's rhinopharynx's flora in Senegal allowed us to identify three major pathogenic germs: S pneumoniae, H influenzae and S pyogenes contributing to a better knowledge of these microorganisms' serotypes, biotypes and antibiotypes.