High human exposure to pyrene (polycyclic aromatic hydrocarbon) in Kinshasa, a capital of the Democratic Republic of Congo

BACKGROUND: Data on human exposure to chemicals in Africa are scarce. A biomonitoring study was conducted in a representative sample of the population in Kinshasa (Democratic Republic of Congo) to document exposure to polycyclic aromatics hydrocarbons. METHODS: 1-hydroxypyrene (1-OHP) was measured by HPLC fluorescence in spot urine samples from 220 individuals (50.5% women), aged 6–70 years living in the urban area and from 50 additional subjects from the sub-rural area of Kinshasa. Data were compiled as geometric means and selected percentiles, expressed without (μg/L) or with creatinine adjustment (μg/g cr). Multiple regression analyses were applied to factors (creatinine, grilled meat habits and smoking habits) influencing 1-OHP (stepwise procedure, criteria: probability F to enter ≤ 0.05 and probability F to remove ≥ 0.10). RESULTS: According to the regression models, creatinine, grilled meat habits and smoking habits contribute to explain 45% of the variation in population’s urinary 1-OHP by the environmental exposure. Overall, living in urban area of Kinshasa was associated with increased levels of 1-OHP in urine as compared to a population living in the sub-rural area [GM: 1.8 μg/L (n = 220) versus 1.4 μg/L (n = 50), p < 0.01] as well as compared to the reference values from databases involving American or German populations. CONCLUSION: This study reveals the high pyrene (PAH) exposure of the Kinshasa population. However, more work, with a rigorous design in the exposed population (monitoring of air concentrations and identifying other sources of pyrene –PAH exposure), is needed to establish further documentation

Blood lead levels in children after phase-out of leaded gasoline in Kinshasa, the capital of Democratic Republic of Congo (DRC)

BACKGROUND: The phasing out of lead from gasoline has resulted in a significant decrease in blood lead levels (BLLs) in children during the last two decades. Tetraethyl lead was phased out in DRC in 2009. The objective of this study was to test for reduction in pediatric BLLs in Kinshasa, by comparing BLLs collected in 2011 (2 years after use of leaded gasoline was phased out) to those collected in surveys conducted in 2004 and 2008 by Tuakuila et al. (when leaded gasoline was still used). METHODS: We analyzed BLLs in a total of 100 children under 6 years of age (Mean ± SD: 2.9 ± 1.6 age, 64% boys) using inductively coupled argon plasma mass spectrometry (ICP – MS). RESULTS: The prevalence of elevated BLLs (≥ 10 μg/dL) in children tested was 63% in 2004 [n = 100, GM (95% CI) = 12.4 μg/dL (11.4 – 13.3)] and 71% in 2008 [(n = 55, GM (95% CI) = 11.2 μg/dL (10.3 – 14.4)]. In the present study, this prevalence was 41%. The average BLLs for the current study population [GM (95% CI) = 8.7 μg/dL (8.0 – 9.5)] was lower than those found by Tuakuila et al. (F = 10.38, p <0.001) as well as the CDC level of concern (10 μ/dL), with 3% of children diagnosed with BLLs ≥ 20 μg/dL. CONCLUSION: These results demonstrate a significant success of the public health system in Kinshasa, DRC-achieved by the removal of lead from gasoline. However, with increasing evidence that adverse health effects occur at BLLs < 10 μg/dL and no safe BLLs in children has been identified, the BLLs measured in this study continue to constitute a major public health concern for Kinshasa. The emphasis should shift to examine the contributions of non-gasoline sources to children’s BLLs: car batteries recycling in certain residences, the traditional use of fired clay for the treatment of gastritis by pregnant women and leaded paint

S-phenylmercapturic acid (S-PMA) levels in urine as an indicator of exposure to benzene in the Kinshasa population

Background and objectives: Data on human exposure to chemicals in Africa are scarce. A biomonitoring study was conducted in a representative sample of the population in Kinshasa (Democratic Republic of Congo) to document exposure to benzene. Methods: S-phenylmercapturic acid (S-PMA) was measured by LC-MS/MS in spot urine samples from 220 individuals (50.5% women), aged 6-70 years living in the urban area and from 50 additional subjects from the sub-rural area of Kinshasa. Data were compiled as arithmetic means, geometric means, percentile 95th and range expressed in μg/L. Results: Overall, living in urban Kinshasa was associated with increased levels of S-PMA in urine as compared to a population living in the sub-rural area. Increased levels were also found by comparison with some date from literature. Conclusions: This study reveals the high benzene exposure of the Kinshasa population requiring the determination of benzene concentrations in ambient air of Kinshasa and limit values for the protection of human health. © 2013 Elsevier GmbH

Biomonitoring de l'exposition aux polluants environnementaux dans la population de Kinshasa

Contexte et objectif de la recherche. La pollution chimique constitue une préoccupation majeure de santé publique dans les pays industrialisés mais également dans l’hémisphère sud, et plus particulièrement en Afrique. Des données relatives à l’exposition de l’Homme aux substances chimiques ne sont actuellement pas disponibles pour la ville de Kinshasa. L’objectif de cette thèse était de dresser un état des lieux de l’imprégnation de la population kinoise à quelques polluants environnementaux majeurs. Méthodes. Le biomonitoring d’exposition a été utilisé comme méthode d’évaluation des expositions environnementales dans un échantillon représentatif de la population urbaine de Kinshasa [n = 275, 147 (53%) femmes, âge moyen ± SD (amplitude): 27 ± 23 ans (1-70) ans, 79 (29%) fumeurs]. 60 personnes additionnelles vivant dans le milieu rural ont été incluses dans l’étude comme contrôle. Le Pb sanguin a été dosé par GF-AAS, les éléments en trace (Al, As, Ba, Cd, Cr, Co, Cu, Pb, Mn, Hg, Mo, Ni, Se, V, Zn), le 1-OHP (métabolite du pyrène, HAP), la cotinine (métabolite de la nicotine) et le SPMA (métabolite du benzène) ont été dosés dans les urines par ICP-MS (HG-FAS ou CV-AAS), UPLC-fluorescence, HPLC-UV et LC-MS/MS respectivement. Les données ont été exprimées en moyennes géométriques et en percentiles pour les biomarqueurs étudiés. Principaux résultats. (1) L’étude pilote réalisée en 2004 sur la plombémie à Kinshasa (n = 485) suggérait une imprégnation saturnine relativement importante dans la population urbaine de Kinshasa et particulièrement chez les enfants de moins de 6 ans (n = 100). Dans cette étude, 63% de ces enfants avaient des plombémies supérieures au seuil d’intervention (100 μg/L) fixé depuis 1991 par les CDC américains pour la mise en place d’interventions environnementales et éducatives. Dans la population adulte, l’exercice d’une profession avec risque potentiel d’exposition à l’essence (garagistes, chauffeurs de taxi, convoyeurs et pompistes) était associé à un supplément de plombémie de l’ordre de 65 µg/L. (2) Les valeurs de la plombémie mesurée en 2008 confirment l’imprégnation observée en 2004 et particulièrement chez les enfants de moins de 6 ans. Les enquêtes environnementales effectuées dans les habitations de ces enfants montrent que 43% de la variation de la plombémie infantile sont expliqués par les facteurs environnementaux de risque (Pb dans l’air intérieur des maisons, usage des remèdes traditionnels contenant du Pb). (3) Les études réalisées sur l’urine fournissent également des données à propos de plusieurs substances dans la population urbaine de Kinshasa. Ces études mettent en évidence une importante imprégnation aux HAP aussi bien chez les enfants que chez les adultes. Les valeurs observées pour l’Al, As inorganique, Hg suggèrent également une imprégnation relativement importante. (4) L’analyse multivariée indique que vivre dans la zone urbaine de Kinshasa est associé à un excès d’imprégnation pour la majorité des biomarqueurs étudiés (As inorganique, Ba, Cd, Cr, Pb sanguin, V, 1-OHP, SPMA, Cotinine) par rapport à la zone rurale. Conclusion. L’ensemble des études réalisées ont permis de fournir une première base de données pour l’évaluation de l’exposition aux polluants chimiques dans la ville de Kinshasa. Ces données seront utiles pour les études de tendance et/ou de comparaison avec d’autres populations. Ces études ont surtout permis de révéler une imprégnation relativement importante aux HAP, au Pb ainsi qu’à l’Al, l’As inorganique et au Hg. Ceci démontre l’existence d’un problème majeur de santé publique. La combustion de bois; les habitudes alimentaires; l’usage des remèdes traditionnels populaires et de l’essence au Pb; les activités artisanales de recyclage des batteries; la pollution automobile peuvent représenter des sources significatives d’exposition dans la ville de Kinshasa nécessitant des informations complémentaires, des actions correctives et la mise en place d’une réglementation appropriée.(MED 3) -- UCL, 201

S-phenylmercapturic acid (S-PMA) levels in urine as an indicator of exposure to benzene in the Kinshasa population

Background and objectives: Data on human exposure to chemicals in Africa are scarce. A biomonitoring study was conducted in a representative sample of the population in Kinshasa (Democratic Republic of Congo) to document exposure to benzene. Methods: S-phenylmercapturic acid (S-PMA) was measured by LC-MS/MS in spot urine samples from 220 individuals (50.5% women), aged 6-70 years living in the urban area and from 50 additional subjects from the sub-rural area of Kinshasa. Data were compiled as arithmetic means, geometric means, percentile 95th and range expressed in μg/L. Results: Overall, living in urban Kinshasa was associated with increased levels of S-PMA in urine as compared to a population living in the sub-rural area. Increased levels were also found by comparison with some date from literature. Conclusions: This study reveals the high benzene exposure of the Kinshasa population requiring the determination of benzene concentrations in ambient air of Kinshasa and limit values for the protection of human health. © 2013 Elsevier GmbH

Elevated blood lead levels and sources of exposure in the population of Kinshasa, the capital of the Democratic Republic of Congo

The objective of this study was to determine blood lead levels (BLLs) and the possible sources of exposure in the population of Kinshasa, the capital of the Democratic Republic of Congo. A cross-sectional survey was carried out from January to May 2008 in a representative sample of the Kinshasan population. BLL was measured in 275 individuals (53.4% women) aged 1–70 years in the urban area of Kinshasa and from 60 additional subjects in the rural area. Pb was also determined in environmental specimens (air and soil, indoor and outdoor). BLL in the study population ranged from 2.9 to 49.3 μg/dl (median, 9.9 μg/dl). The median BLL among children aged <6 years was 11.5 μg/dl (range: 3.0–37.8 μg/dl). Of these children, 71% had elevated BLL (≥10 μg/dl) and 22% had BLL ≥20 μg/dl. The proportion of elevated BLL (≥10 μg/dl) was higher for children aged <3 years than for children aged 3 to 5 years (97% vs 56%). A higher prevalence of elevated BLL was observed in urban compared with rural children (71% vs 20%). Significantly higher BLLs were also found in children whose mother consumed fired clay during pregnancy. Residential informal activities in the recycling of car batteries also contributed to elevated BLL in children. The elevated background of Pb exposure in the Kinshasan population indicates a public health issue that requires corrective actions. Pb-contaminated dust and air in children's home is an issue of public health concern. The use of leaded gasoline and the activities of car battery recycling in certain residences appear to constitute the main sources of exposure in the city of Kinshasa. The traditional use of fired clay for the treatment of gastritis by pregnant women is another significant contributor for elevated BLL in children

Cadmium, manganese, mercury and lead in the general adult population of Kinshasa, DR Congo

Background and Aim. Many metals are of health concern due to their toxic proprieties and health impairments in the human body. To evaluate values for the internal exposure in the general population, the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) and the International Union of Pure and Applied Chemistry (IUPAC), recommend the use of reference intervals (RIs) of metals as an indicator of the background exposures. This work aimed to derive RIs for Cd, Hg, Mn and Pb in the blood and urine of the adult population living in Kinshasa (n = 396, aged 18–70 years with 210 females). Methods. Levels of metals were measured using Inductively Coupled Argon Plasma - Mass Spectrometry (ICP-MS). Results. In blood, the proposed RIs [P5-P95 (GM)] were 0.089–2.365 µg/L (0.262), 41.41–199.20 µg/L (84.43), 0.100–1.964 µg/L (0.450) and 6.014–15.380 µg/L (9.394) for Cd, Pb, Hg and Mn, respectively. Urinary levels [(P5-P95 (GM)] were 0.142–1.430 µg/L (0.458) for Cd, 1.910–17.840 µg/L (5.424) for Pb, 0.349–2.295 µg/L (0.816) for Hg and 0.063–1.340 µg/L (0.188) for Mn. Conclusion. Except for Pb, levels of all metals were significantly lower than those found in the same city in 2012 and similar to databases involving non-occupationally exposed populations from other countries, probably due to exclusion criteria of metal exposure applying in the present survey (occupationally exposed to the studied metals, smoking habits, amalgam tooth fillings, fish consumption habit more than one time per week, etc.). These background metal exposures will be useful for future occupational and/or environmental surveys as well as undertaking a reliable regulation of chemical exposure in Kinshasa via a national HBM program

Tentative reference values for environmental pollutants in blood or urine from the children of Kinshasa

The DRC, as most of African nations, does not have a national biomonitoring programme and there is a lack of information on background levels of environmental pollutants in the general DRC population, particularly in children. The focus of the data presented in this report aims to establish the background levels of a range of environmental pollutants in urine or blood from the children population of Kinshasa. Based on the representative data collection of the Kinshasa population, the survey selected 125 children aged 1-14years and living in Kinshasa (6years on average, 56% of girls, 100% of non-smokers, without amalgam fillings and consumers of fish 3 times per week). Biomarkers of a range of metals (As, Cd, Hg and Pb), pyrene (PAH) and benzene were analyzed in the blood or urine samples. Globally, the results indicate that the exposure levels of children living in Kinshasa are 10 times higher than those published by the American, Canadian and German children surveys. This study provides the first Reference Values of environmental pollutants [As, Cd, Hg, Pb, pyrene (PAH) and benzene] in the Kinshasa children population and reveals elevated levels of all biomarkers studied. The data set of this study may allow environmental and health authorities of DRC to undertake a national biomonitoring programme, especially with four insights for the protection of human heath