Horizontal and Vertical Distribution of Heavy Metals in Farm Produce and Livestock around Lead-Contaminated Goldmine in Dareta and Abare, Zamfara State, Northern Nigeria.

Background. Hitherto studies in response to the June 2010 lead poisoning, Zamfara State, Nigeria, have focused on clinical interventions without information on livestock and other metals. Objective. This study has investigated the distribution of heavy metals in farm produce and livestock around lead-contaminated goldmine in Dareta and Abare, Zamfara State, Nigeria. Methods. Vegetables, soil, water, blood, and different meat samples were harvested from goat, sheep, cattle, and chicken from Dareta, Abare, and Gusau communities. The samples were digested with 10 mL of a mix of nitric and perchloric acids; the mixture was then heated to dryness. Lead, cadmium, zinc, chromium, copper, magnesium, and nickel were analysed using flame Atomic Absorption Spectrophotometer. The daily intake, bioaccumulation factor, and target hazard quotient (THQ) were calculated. Results. Chicken bone-muscles from Dareta had the highest concentrations of lead, zinc, and nickel (28.2750, 16.1650, and 4.2700 mg/kg, resp.), while chicken brain had the highest levels of cadmium, magnesium (0.3800 and 67.5400 mg/kg), and chromium (6.1650 mg/kg, kidney tissue inclusive). Conclusion. In addition to lead, cadmium may also be of concern in the contaminated mining communities of Zamfara State, Nigeria, given the high levels of cadmium in meat and vegetables samples from these areas.

Safety Evaluation of Potential Toxic Metals Exposure from Street Foods Consumed in Mid-West Nigeria.

Objective. Street-vended foods offer numerous advantages to food security; nevertheless, the safety of street food should be considered. This study has investigated the level of potential toxic metal (Pb, Cd, Hg, Sb, Mn, and Al) contamination among street-vended foods in Benin City and Umunede. Methods. Twenty street food samples were purchased from vendors at bus stops. Metals were analyzed with atomic absorption spectrophotometry. The methods developed by the US EPA were employed to evaluate the potential health risk of toxic metals. Results. The concentrations of the toxic metals in mg/kg were in the range of Pb (0.014-1.37), Cd (0.00-0.00017), Hg (0.00-0.00014), Sb (0.00-0.021), Mn (0.00-0.012), and Al (0.00-0.22). All the toxic metals except Pb were below permissible limit set by WHO, EU, and USEPA. The daily intake, hazard quotient, and hazard index of all toxic metals except for Pb in some street foods were below the tolerable daily intake and threshold value of 1, indicating an insignificant health risk. Total cancer risk was within the priority risk level of 1.0E - 04 but higher than the acceptable risk level of 1E - 06. Conclusion. Consumption of some of these street foods is of public health concern.

Spermatoxic effects of operation sweep herbal supplement in male albino rats.

Operation Sweep (OPS) de rheumatism powder is a registered Nigerian poly-herbal medicine. The acute and sub-chronic testicular toxicology of the OPS powder was investigated in male albino rats. The rats, divided into 10 per group, received aqueous extract of the OPS powder, orally, at 0, 0.75, 1.50, 2.25 g/kg for 30 days. Animals were sacrificed on day 30; the testes and epididymis were excised and weighed. The testes were processed for histological analysis, and the epididymis was used for sperm quality: epididymal sperm count (ESC), epididymal sperm motility (ESMot) and the epididymal sperm morphology (ESMor) determination. The results showed a non-significant increase in the body weights of the treated groups. Treatment with OPS caused a significant (p < .05) reduction of the relative weight of the epididymis in the 2.25g/kg dose group; a significant (p < .05) decrease in the ESC and active ESMot, an increase in the dead ESMot, and a nonsignificant (p > .05) effect on the ESMor. Histologic examination of the testes indicated no serous pathological changes except for some mild vascular congestion at 1.5 and 2.25 g/kg. This study suggests that the aqueous extract of the OPS powder may cause epididymal toxicity as shown in the adverse effect on sperm quality.

Hepatotoxic and hematologic effects of an aqueous extract of the Nigerian herbal remedy U&D Sweet Bitter in male albino rats.

The hepatotoxic and hematologic effects of the extract of a Nigerian herbal remedy, U&D Sweet Bitter, were investigated in mature Wistar albino rats. Twenty male albino rats were allocated into four dose groups of five rats each. Food and fluid intake, body weight, absolute and relative weight of the liver, and hematologic and biochemical parameters were measured. The absolute and relative weights of the liver significantly decreased (p < or = .05) when compared with controls. Doses of 539, 1077, or 1616 mg/kg of U&D Sweet Bitter given orally for 90 d induced a significant (p < .05) dose-dependent increase in aspartate aminotransferase and alkaline phosphatase and decrease in alanine aminotransferase compared with controls. Hepatic and haematologic parameters of treated groups were significantly different from those of controls. Histologic examination revealed that U&D Sweet Bitter induced severe necrosis and edema.

Nephrotoxic effects of aquoeus extract U & Dee Sweet Bitter (a Nigerian herbal remedy) in male albino rats.

The effect of the extract of U & Dee Sweet Bitter, a Nigerian herbal remedy on the kidney was investigated in matured Wistar albino rats. Twenty male albino rats were allocated into four dose groups of five rats each, namely 0.00, 539, 1077, 1616 mg/kg of the herbal product orally for 90 days. Animals had access to deionized water and were fed ad libitum with rat chow for 90 days. The feed and fluid consumption of the animals were measured on daily basis, and the body weight was measured weekly. After 90 days, the animals were anaesthetized with ether, bled, sacrificed, kidney excised, and weighed. The parameters measured included food and fluid intake, body weight, absolute and relative weight of the kidney. A nonsignificant increase (p > .05) in feed and fluid intake occurred in all treated animals and a significant decrease (p < .05) in absolute weight of the kidney in all the treated animals when compared with the control. The administration of 539, 1077, and 1616mg/kg of U & Dee Sweet Bitter caused a significant (p < .05) dose-dependent increase in creatinine, whereas a significant dose-dependent decrease for urea was noted compared with the control. Histological study showed that U & Dee Sweet Bitter at all doses caused renal pathologic changes that include tubular necrosis, inflammation of the interstitial and glomerulus, and disorganization of the entire architecture. The results are indicative of nephrotoxicity.

Lead levels in paint flakes from buildings in Nigeria: a preliminary study.

Lead is a malleable metal previously used to improve the durability and color luster of paint applied in homes and on industrial structures such as bridges. Lead has deleterious effects on multiple organs in humans. There is paucity of information on the extent of the use of lead-based paint in Nigerian houses. This study has attempted to estimate the extent of use of lead-based paint in buildings in Eastern Nigeria using 168 buildings. Flaked paint samples were collected from residential, church, commercial, and school buildings from four most populous cities in Eastern Nigeria namely Enugu, Onitsha, Aba, and Port Harcourt, and they were digested using conc HNO(3):HCLO(4) (1:1) and analyzed using atomic absorption spectrophotometer. The lead levels from buildings in Enugu ranged from 39.385 +/- 1.111-69.843 +/- 4.886 mg/kg. The highest level of lead was found in Onitsha ranging from 49.503 +/- 0.000-74.352 +/- 0.571 mg/kg. Residential buildings, which mainly serve the under privileged populations, has the highest lead level in this study. In Aba, the highest lead level (66.432 +/- 0.013 mg/kg) was found in commercial buildings aged 5-10 years. The lead levels in paint flakes from buildings in the four cities tended to decrease with increasing age of the buildings. Taken together all the building paint flakes from the four cities had lead levels higher than the United States Environmental Protection Agency permissible level of 5 mg/kg. There is a need for primary intervention strategy to reduce the paint lead levels in Nigeria.

Acid rain phenomenon in niger delta region of Nigeria: economic, biodiversity, and public health concern.

Rain samples were collected from Warri and Port Harcourt, two major oil-producing cities of Nigeria in April-June, July-August, and September-October 2005 and 2006. Awka, a "non-oil" city was used as control. Samples were collected from three points, using clean plastic basins fastened to a table, 2 m above ground level and 115 m away from tall buildings and trees. Water samples were filtered and acidity determined using digital pH meter. The results show that the rain samples were acidic. The pH values for the 2 years under study show that the rainfall in Warri was more acidic than that of Port Harcourt. Oil exploration and other anthropogenic sources may be responsible for the acid rain in the Niger Delta region of Nigeria.

Heavy metal levels and physico--chemical quality of potable water supply in Warri, Nigeria.

The interaction between man's activities and the environment is gaining world wide attention. Warri an oil producing community in Delta State of Nigeria is faced with environmental oil pollution. Since open and underground water bodies are regarded as final recipients of most environmental pollutants, this study sought to provide data on the levels of the physico-chemical parameters and contaminants in Warri metropolitan water supply. This study investigated the cadmium, lead and chromium using Atomic Absorption Spectrophotometer, physico-chemical properties such as pH, temperature, total suspended solid TSS, total dissolved solid TDS, electrical conductivity EC, biological oxygen demand BOD, dissolved oxygen DO, chemical oxygen demand COD, and total coliform count of potable water sources in Warri. Ekpan River was found to have 1.2 mg/L of cadmium, 1.0 mg/L of chromium, 1.20 mg/L of lead and 2.0 mg/L of manganese. The heavy metals levels and the pollution parameters were lowest in the borehole water samples, except pH which is more acidic in borehole water samples and conductivity which is more in well water samples in all the sampling stations. Some of the parameters were above WHO standards.

Heavy metals other than lead in flaked paints from buildings in Eastern Nigeria.

Cadmium, chromium, iron, zinc, and copper levels of flaked paints collected from fifty buildings of four major cities - Enugu, Onitsha, Aba, and Port Harcourt in Eastern Nigeria were studied. Fifty samples of the flaked paints were ground with laboratory pestle and mortar, 2 g of fine ground paints that could pass through a 0.5-mm sieve were digested with 15 ml concentrated nitric acid and perchloric acid at a ratio of 1:1 and analyzed for cadmium, chromium, iron, zinc and copper using atomic absorption spectrophotometer 500. Cadmium ranged from 9.032 +/- 0.000 to 10.575 +/- 0.000 and 6.845 +/- 0.000 to 10.028 +/- 0.002 mg/kg in Enugu and Onitsha, respectively. In Aba and Port Harcourt, the levels of cadmium ranged 7.464 +/- 0.002-9.343 +/- 0.002 and 7.293 +/- 0.002-9.395 +/- 0.000 mg/kg, respectively. Chromium levels were significantly lower in Enugu (range 0.940 +/- 0.000-12.793 +/- 0.002 mg/kg) when compared with the values from other cities namely Onitsha (range 1.613 +/- 0.002-15.140 +/- 0.000 mg/kg), Aba (range 15.206 +/- 0.000-39.215 +/- 0.000 mg/kg) and Port Harcourt (range 33.118 +/- 0.002-55.418 +/- 0.002 mg/kg). The highest levels (mg/kg) of iron (11,908.150 +/- 0.000), zinc (31.508 +/- 0.002) and copper (7.588 +/- 0.002) were seen in buildings from Enugu aged 11 years and above. The iron level (mg/kg) ranged from 1391.750 +/- 0.000 to 10,476.845 +/- 0.000, 1450.176 +/- 0.000 to 11,580.750 +/- 0.000 and 3314.913 +/- 0.002 to 8162.333 +/- 0.002 in Onitsha, Aba, and Port Harcourt, respectively. Zinc levels were significantly lower in Onitsha than in Aba and Port Harcourt. Age of building did not seem to affect the levels of these metals namely iron, zinc and copper from these cities. This study shows that flaked paints increase the environmental heavy metal burden in Nigeria.

Liver and kidney function tests amongst paint factory workers in Nkpor, Nigeria.

Lead, cadmium, nickel and other industrial metals used as part of paint varnishes have been reported to have adverse health implications. An evaluation study on some toxicological effects of occupational exposure to paint, among 25 occupationally exposed artisans and 25 students (control) of Ichi Technical College, Ichi Ekwusigo Local Government Area, Anambra State, Nigeria was carried out. Heavy metals were analysed by atomic absorption spectrophotometry and standard assay procedures were employed for biochemical parameters. The biochemical indices used include serum electrolytes urea, creatinine, alanine (ALT) and aspartate aminotransferases (AST), alkaline phosphatase (ALP), conjugated and total bilirubin. Others include blood lead, serum cadmium and nickel. Our results showed that occupational exposure of humans to paints increased the blood lead (39 +/- 4 microg/dL), serum cadmium (13 +/- 1 microg/dL) and nickel (63 +/- 1 microg/dL), when compared with non-paint factory workers (PFW) lead (17 +/- 4 microg/dL), serum cadmium (9 +/- microg/dL) and nickel (25 +/- 44 microg/dL), significantly at P < 0.05 lower values were observed for serum sodium (138.96 +/- 0.58 mmol/L), bicarbonate (26.88 +/- 0.39 mmol/L), urea (3.15 +/- 0.13 mmol/L) and creatinine (80.48 +/- 1.04 micromol/L) for paints factory workers when compared with non-paint factory workers, sodium (139.84 +/- 0.62 mmol/L), bicarbonate (26.20 +/- 0.22 mmol/L), urea (3.44 +/- 0.11 mmol/L) and creatinine (80.40 +/- 1.55 micromol/L); at P > 0.05. The activities of AST (10.36 +/- 0.58 micro/L), ALT(8.76 +/- 0.47 micro/L) and ALP (47.12 +/- 3.33 micro/L) in PFW were slightly elevated compared with non-PFW. Our result indicates that occupational exposure of humans to heavy metals in paints may have long term deleterious effects on liver and renal functions. In conclusion, it should be noted that occupational exposure to cadmium or lead among PFW, may compromise the liver and renal functions in man.

Effect of chloroquine on the bioavailability of ciprofloxacin in humans.

Chloroquine, a front-line drug in the treatment of malaria, has developed widespread resistance, especially to the Plasmodium falciparum strains. Ciprofloxacin is a second-generation quinolone used as a broad-spectrum fluoroquinolone antibacterial agent. The possibility of using ciprofloxacin as an antimalarial, especially in chloroquine-resistant strains, is very promising. They concluded from in vitro studies however that the anti-malarial effect occur at high dose level of ciprofloxacin to achieve the required serum concentrations. Studies have shown that there is little interstrain variability in the in vitro susceptibility of P. falciparum to fluoroquinolones. There is also no cross-resistance between them. Another study stated that 50% inhibition of parasite growth in vitro required 6.6 microg/mL after a high dose of ciprofloxacin was used. They thus concluded that ciprofloxacin should not be used alone. There is need for in vivo studies to ascertain the achievable serum concentration of ciprofloxacin when given alone and when given in combination with chloroquine. The serum concentration of ciprofloxacin was studied when ciprofloxacin was given alone and in combination with chloroquine in humans. Five healthy male volunteers aged (19-31) years who were not taking any of the prescribed medications and had no sensitivity to either ciprofloxacin or chloroquine, each received 500 mg ciprofloxacin orally with 250 mL of water, and after a 2-week wash-out period, 500 mg ciprofloxacin plus 600 mg of chloroquine was administered orally with 250 mL of water after informed consent. A blood sample (2.5 mL) was collected just before taking the drug at 8:00 AM representing 0 hours and continued afterward at 1, 2, 4, 8, 12, and 24 hours the following day. Serum samples were stored at -20 degrees C until analyzed. The minimal inhibitory concentrations (MIC) by diffusion through agar technique was used for the assay of serum ciprofloxacin. The following bioavailability parameters: Cmax, tmax, and AUC 0-24, AUC 0-infinity were calculated. The peak serum concentration Cmax of ciprofloxacin was 3.42 +/- 0.32 microg/mL, which dropped to 2.8 +/- 0.18 microg/mL when chloroquine was taken together with ciprofloxacin. These values were less than the in vitro 12.5 microg/mL concentrations required to inhibit P. falciparum. Though the effect of parasitemia was not ascertained, the in vivo use of ciprofloxacin alone or in combination is doubtful because increasing the dose that will reach the in vitro level will lead to toxicity in vivo.

Lead and cadmium exposures from canned and non-canned beverages in Nigeria: a public health concern.

The lead and cadmium levels of canned and non-canned foods purchased in Nigeria were studied. Fifty samples of these beverages were digested in nitric acid and were analyzed using the Atomic Absorption Spectrophotometer (AAS). The cadmium levels ranged from 0.003-0.081 mg/L for the canned and 0.006-0.071 mg/L for non-canned beverages. About 85.71% of the canned beverages had cadmium levels that exceeded the maximum contaminant level (MCL) of 0.005 mg/L set by US EPA while 82.7% non-canned beverages had cadmium levels exceeding the MCL. The mean and median levels of cadmium exceeded the MCL in both the canned and non-canned beverages. Whereas only 79.3% of the non-canned beverages showed lead levels that exceeded the US EPA's MCL of 0.015 mg/L, 100% of the canned beverages had lead levels that were greater than the MCL. The range of the lead in the canned beverages was 0.002-0.0073 and 0.001-0.092 mg/L for the non-canned beverages. The mean and median values of lead exceeded the MCL in both the canned and non-canned beverages. The calculated amount of lead and cadmium in three beverages were 0.204 mg (204 microg) and 0.177 mg (177 microg), respectively. These represent the estimated intake of a consumer who takes three of the products selected randomly in a week; assuming an average volume of one liter (1 L) for each product. Taken together 86% and 84% of the 50 beverages (canned and non-canned) studied in March, 2005 in Nigeria failed to meet the US EPA criteria for acceptable lead and cadmium levels in consumer products.

Liver and renal function tests in artisans occupationally exposed to lead in mechanic village in Nnewi, Nigeria.

Additives in petroleum solvents have been reported to have adverse health implications. An evaluation study on some toxicological effects of occupational exposure to petroleum products (especially petrol which contains tetraethyl lead) amongst twenty five occupationally exposed artisans and twenty five graduate students of College of Health Sciences, Nnamdi Azikiwe University, Nnewi, Nigeria as controls, was carried out using the following biochemical markers: electrolytes, urea, uric acid, inorganic phosphorus, creatinine, zinc and blood lead, as well as the activities of alanine and aspartate aminotransferases, and alkaline phosphatase. The results showed that occupational exposure of human subjects to lead in petrol increases the concentrations of uric acid (357 +/- 123micro mol/L) and phosphate (1.5 +/- 0.5m mol/L) in exposed subjects compared with unexposed subjects (uric acid 228 +/- 105micro mol/L, phosphate 1.2 +/- 0.41m mol/L; p < 0.01 in both cases). Significantly lower activities were observed for alkaline phosphatase (66 +/- 18.9 iu/L). The activities of alanine aminotransferase (11.4 +/- 4.0 iu/L) and aspartate aminotransferase (15.8 +/- 4.4 iu/L) in occupationally exposed artisans were higher compared with unexposed subjects (alkaline phosphatase = 78 +/- 22.4 iu/L alanine aminotranferase = 6.8 +/- 2.7 iu/L, aspartate aminotranferase = 9.6 +/- 3.5i u+/-L; p < 0.01 in all cases). Occupational exposure of human subjects to lead significantly increased blood lead (59.6 +/- 15.9 microg/dL) and decreased plasma zinc (71.3 +/- 14.4 microg/L) in exposed compared with unexposed subjects (blood lead = 35 +/- 7 microg/dL, zinc = 108.4 +/- 16.9 microg/dL; p < 0.01). The results indicate that occupational exposure to lead in petrol may compromise liver and renal function.

Investigation into the nephrotoxicity of Nigerian bonny light crude oil in albino rats.

The effect of bonny-light crude oil was assessed in adult albino rats. The rats were administered with 200, 400, and 800 mg/kg body weight of the crude oil orally for 7 days. Fluid intake was measured daily, initial and final animal body was recorded. The toxic effects on the kidneys were assessed and histological studies carried out. The results revealed that the kidney cells were damaged; crude oil caused a destruction of the renal reserve capacity. There was a significant increase (p ? 0.05) in creatinine in the high dose group (800mg/kg), and a significant decrease (p ? 0.05) in urea concentration. Histological examination indicates that crude oil induced severe pathologic changes in the forms of necrosis and oedema.

Influence of prokinetics on the gastrointestinal transit and residence times of activated charcoal.

OBJECTIVE: To find the effects of prokinetics, saline cathartics and different charcoal doses on the gastrointestinal transit and residence times of activated charcoal (AC). SETTING: Five undergraduate volunteers of College of Health Sciences, Nnamdi Azikiwe University, Nnewi Campus, Anambra State, Nigeria, were studied. METHODS: After an overnight fast, the volunteers were given 10 g and 20 g AC with and without saline cathartics, in a simple cross-over design in which the subjects served as their own control. In another experiment, the volunteers received 10 g AC and magnesium sulphate, with propantheline (as bromide 15 mg), metoclopramide (as hydrochloride 10 mg), placebo liquid or identical placebo capsule. Gastrointestinal transit and residence times of AC were recorded. RESULTS: Increase in the dose of AC significantly (P < 0.05) decreased the transit, but not the residence time of AC. Addition of saline cathartics (Na2SO4 and MgSO4) decreased both the transit and residence times of AC significantly (P < 0.05). Also, administration of propantheline, but not metoclopramide, produced a significant (P < 0.05) decrease in both the transit and residence times of AC. The transit and residence times were statistically (P < 0.05) different in both the magnesium sulphate group, as well as in the placebo liquid and placebo capsule groups. CONCLUSION: Cathartic efficiency is enhanced by alteration of gastrointestinal motility with propantheline.

Saline cathartics and adsorptive capacity of activated charcoal for doxycycline.

The effects of sodium chloride and sodium citrate on the in vitro adsorption of doxycycline to activated charcoal have been studied. Solutions of doxycycline alone and doxycycline with 7.5 mg/ml cathartic solutions were vortex-mixed for 30 s with different quantities of activated charcoal, incubated for 30 min at 37 degrees C and analyzed for free doxycycline spectrophotometrically at 348 nm. Addition of NaCl had a significant (p<0.05) increase while sodium citrate produced a significant (p<0.05) decrease in the adsorption of doxycycline on activated charcoal. In all, the adsorption doxycycline on activated charcoal obeyed quantity-dependent kinetics.

Effect of activated charcoal on isoniazid absorption in rabbits.

The effect of activated charcoal on gastrointestinal absorption of isoniazid (INH) was determined quantitatively in rabbits. The presence of activated charcoal resulted to about 40% reduction of INH bioavailability as was indicated by reduction in the AUC0-24 hour. The plasma half live (T1/2) and peak plasma concentration (Cmax) of the drug were reduced, while the apparent volume of distribution (Vd) and total clearance (Cl) of the drug were increased in the presence of activated charcoal. The results present an assessment of adsorptive capacity of activated charcoal for INH in vivo and as such could serve as a cheap, effective and readily available means of emergency treatment of INH poisoning.

Some plasma pharmacokinetic parameters of isoniazid in the presence of a fluoroquinolone antibacterial agent.

The effects of ciprofloxacin (CP), a fluoroquinolone antibacterial agent, on the extent of absorption of isoniazid (INH) and on some of its pharmacokinetic parameters were investigated in six healthy female volunteers between the ages of 23 and 32 years. The presence of CP led to increase in the amount of INH and to a slight reduction in its peak plasma concentration (Cmax). There was a 1-hour increase in the time to attain Cmax (tmax) of INH, indicating absorption interaction between the two drugs. This absorption interaction was related to inhibition of cholinergic neurotransmission caused by CP, which is capable of inhibiting gastric motility, leading to a delay in gastric emptying. The rate of elimination (K) and plasma half-life (t1/2) of INH were not significantly affected (P = 0.05). The extent of absorption interaction that may have occurred (based on values of 24-hour values for area under the concentration curve, Cmax, Tmax, K, and t1/2) was considered to be of no therapeutic consequence, and the coadministration of the two drugs may be recommended in clinical practice.