Copper, Iron and Zinc concentrations of tobacco leaves and ready-to-use snuff products on sale in Imo State Southeastern Nigeria

This paper reports the results of the determination of the concentrations of Zn, Cu, and Fe in tobacco leaves and snuff products on sale in some regional markets in Imo State, Southeastern Nigeria. The samples were ashed at 550°C, mineralized with acid and the metal concentrations measured using flame atomic absorption spectrophotometer. The mean metal concentrations are 843 ± 46 mg kg-1 for Fe, 79 ± 4 mg kg-1 for Zn, and 22 ± 2 mg kg-1 for Cu in snuff samples and; 951 ± 78 mg kg-1 for Fe, 83 ± 2 mg kg-1 for Zn, and 24 ± 2 mg kg-1 for Cu in tobacco leaves. Comparably, higher metal concentrations were obtained in tobacco leaves than in the snuff products, and the metal concentrations varied according to the regional markets from where they were purchased. The results of this study indicate that snuff products could constitute trace metal exposure routes to users.Keywords: snuff; trace metals; tobacco; toxicology; Nigeri

Cadmium determination in cigarettes available in Nigeria

Cadmium (Cd) contents were determined in 30 brands of tobacco cigarette commonly available in Nigeria by atomic absorption spectrophotometry. The concentration of Cd in the cigarettes ranged from 0.7 to 2.3 g/g dry weight with mean 1.48 ± 0.46 g/g. Higher Cd concentrations were found in importedbrands (1.52 ± 0.46 g/g) compared to the Nigerian brands (1.10 ± 0.35 g/g). Relatively lower Cd values were observed in cigarettes from developing countries (~ 1.3 g/g) compared to brands from developed countries (>1.3 g/g). The average Cd content of cigarettes available in Nigeria is 1.28 g per cigarette and a person who smokes 20 cigarettes per day is estimated to increase his daily Cd retention by approximately 1 g/day (0.53 – 1.65 g/day). The results indicate that smoking and exposure to cigarettesmoke is a confounder to be taken into account when carrying out epidemiological studies on human exposure to cadmium

Trace metal contents of facial (make-up) cosmetics commonly used in Nigeria

Several facial cosmetics available in Nigeria were analyzed for their contents of the heavy metals; lead, cadmium, chromium, nickel, zinc and iron. The levels of chromium, iron and zinc were much higher in the samples than those of the non-essential toxic metals; lead, cadmium and nickel. The range of the geometric average for the various cosmetics is: Fe, 97-256 g/g; Ni, 8-13 g/g; Pb, 87-123 g/g; and Zn, 88-101 g/g. The geometric mean values obtained for Cr and Cd were generally below 40 g/g and about 1 g/g, respectively. Our result indicates that these cosmetics are relatively safer to use when compared to the lead-based kwali eye make-up commonly available in Nigeria. These data indicate that the continuous use of these cosmetics could result in an increase in the trace metal levels in the ocular system and the human body beyond acceptable limits. The application of these cosmetics needs to be considered as a source of lead in evaluating patients with symptoms of lead intoxication in regions where this practice is common

Determination of lead and cadmium contents of dry cell batteries available in Nigeria

Lead and cadmium content of different brands and sizes (N=38) of dry cell batteries (zinc-carbon Leclanche systems) available in Nigeria were determined by atomic absorption spectrometry after acid digestion. The average Pb and Cd content of the dry cells are 1077.9±751.7mg/kg (Range 42-3170mg/kg) and 108.3±81.4mg/kg (Range 4.6-410mg/kg) respectively. The mean Pb and Cd contents of dry cells with metal outer cover were significantly lower (p < 0.005) than the corresponding values for dry cells with non-metallic cover. The highest Pb and Cd values were observed in dry cell batteries imported from China. Higher mean Pb and Cd value were observed in dry cells from China (1368.36 vs. 151.47mg/kg), compared to values for dry cells from Indonesia (1032 vs. 84.4mg/kg), Japan (715.2 vs. 131.48mg/kg) and Korea (1137.5 vs. 81.45). Lower Pb and Cd values were obtained in dry cells from Malaysia (709 vs. 12.5mg/kg), Spain (702 vs. 65.8mg/kg), United States (303 vs. 11.1mg/kg) and in the only surviving local brand (408 vs. 34.5mg/kg).Our study revealed that there is an urgent need to introduce an adequate well-established system for collection, separation, storage and management of municipal and industrial wastes containing primary and secondary battery wastes and similar toxic materials to halt the open burning of such wastes within inhabited areas. There is an urgent need to develop in Nigeria an appropriate technology following the principles of waste minimization and sustainable development. Journal of Applied Sciences and Environmental Management Vol. 10 (3) 2006: 37-4

Assessment of Heavy Metal Contents of End-Of-Life Computer Monitor Cathode Tubes and Plastic Casings

Development and innovation in computer technology have led to the generation of large quantities of end-of-life computing equipment with the attendant challenge of environmentally sound management, especially in developing countries. This study evaluated the heavy metal contents of the cathode ray tube (CRT) and the plastic casing of thirty (30) end-of-life computer monitors of different brands, years of manufacture (spanning 1981-2005) and countries of manufacture. The specimens were analysed for Pb, Cu, Cr, Zn, Cd, and Ni using atomic absorption spectrophotometer after acid digestion. The mean concentrations of metals in the CRTs varied widely: 1400-14300 mg/kg for Pb; 291-1750 mg/kg for Zn; &lt;0.1-129 mg/kg for Cu; &lt;0.1-15 mg/kg for Ni; &lt;0.1-16.3 mg/kg for Cr, and &lt;0.1-4.0 mg/kg for Cd. The Pb concentrations of all the CRT samples, with mean 5120±3000 mg/kg (range: 1400- 14300 mg/kg), exceeded the 1000 mg/kg Pb limit in the EU Directive on the Restriction of Hazardous Substances (RoHS) and the Total Threshold Limit Concentrations (TTLC) used by the USA Department of Toxic Substances and Control (DTSC), for characterizing waste as hazardous. For the plastic casings, the Cu and Cd concentrations in 10 % and 20 % of the samples respectively, exceeded the TTLC. The results of this study show that the CRTs are hazardous waste requiring environmentally sound management and the crude methods of management in Nigeria which include disposal at open dumpsites and surface water, as well as recycling using crude techniques are highly dangerous, exposing man and the ecosystem to toxins

Multielement analyses of human scalp hair samples from three distant towns in southeastern Nigeria

Hair samples were collected from three distant towns in Southeastern Nigeria and analyzed for their contents of the trace metals, Pb, Cd, Zn, Ni, Cu, and Cr by atomic absorption spectrometry. Higher geometric mean values for Pb, Zn, Ni, Cu, and Cr were obtained in hair samples of donors from theindustrialized areas, Aba and Onitsha. Higher levels of Pb and Cr were observed in hair samples of male donors while higher levels of Zn and Cu were obtained in hair samples from the unindustrialized area, Isuochi. For the general population studied, geometric mean values of 65.4 &igrave;g/g (range 9.1 to 194.5 &igrave;g/g); 1.2 &igrave;g/g (0.4 to 6.6 &igrave;g/g); 146.2 &igrave;g/g (57.7 to 510 &igrave;g/g); 26.4 &igrave;g/g (5.0 to 143.2 &igrave;g/g); 117.2 &igrave;g/g (29.4 to 363.5 &igrave;g/g); 35.1 &igrave;g/g (19.5 to 60.6 &igrave;g/g) were obtained for the metals, Pb, Cd, Zn, Ni, Cu, and Cr, respectively. Our result indicates that ~ 89% of the population had Pb levels &gt;30 &igrave;g/g, indicative of occupational exposure, while about 20% had levels &gt;110&igrave;g/g which is considered dangerous

Lead Exposure: A Contributing Cause of the Current Breast Cancer Epidemic in Nigerian Women

Breast cancer incidence in Nigerian women has significantly increased during the past three decades in parallel with the rapid industrialization of that country. This suggested that the associated widespread contamination of the soil and of the water supplies by lead (Pb) and other industrial metals was a major contributing cause. Because of its many domestic, industrial, and automotive uses, Pb is of particular concern as it has been shown to promote the development of mammary tumors in murine mammary tumor virus-infected female C3H mice at levels as low of 0.5 ppm Pb in the drinking water. Lead belongs to the group of selenium-antagonistic elements that interact with selenium (Se), abolishing its anti-carcinogenic effect. Lead on chronic, low-level exposure in addition also accelerates tumor growth rates. Higher levels of Pb were found in blood and head hair samples of newly diagnosed patients with breast cancer, all with infiltrating ductal carcinoma, the most common form of breast cancer in Nigeria, seen at Obafemi Awolowo University, than in cancer-free controls from the same area. Evidence for interactions between Pb and Se was obtained from blood, hair, and tumor biopsy tissue analyses. Furthermore, the Pb levels in hair samples of the patients were directly correlated with the volumes of their tumors, in accord with the tumor growth-promoting effects of Pb. Conversely, Se levels in hair and blood were inversely correlated with the tumor volumes, consistent with the anti-proliferative effects of Se. Several other elements, e.g., Cd, Hg, Cr, Sn, and As, were detected in the scalp hair of the patients and the controls, although at significantly lower levels than those of Pb. However, correlation calculations revealed them also to interact with Se, suggesting that only a fraction of the Se in organs and tissues is actually present in bioactive forms. In metal-exposed subjects, a state of latent Se deficiency may exist, resulting in depressed immune functions and increased cancer susceptibility. Evidence is presented to show that Pb and other metals also interact with iodine, another vitally important essential trace element believed to protect against breast cancer development. Public health programs aiming at lowering the breast cancer risk of Nigerian women thus will have to include effective measures to protect the population from exposures to Pb and other industrial metals that are presently contaminating the environment and the water supplies