Health risk implications of lead, cadmium, zinc, and nickel for consumers of food items in Migori Gold mines, Kenya

Ngure, Veronica; Kinuthia, Geoffrey

doi:10.1016/j.gexplo.2019.106430

Cited by 24 publications

(11 citation statements)

References 50 publications

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“…One part was air dried at room temperature for several days while the remaining part was lyophilized (freeze dried). Both air dried and lyophilized algae samples were ground and sieved to obtain a ne powder as described by Ngure & Kinuthia [67]. The powder was then weighed and packaged in well labeled brown small envelops to await metal analysis.…”

Section: Methodsmentioning

confidence: 99%

Urban mosquitoes and filamentous green algae: their biomonitoring role in heavy metal pollution in open wastewater channels in Nairobi, Kenya

Kinuthia

Ngure

Kamau

2021

Preprint

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Background Levels of Mercury (Hg), Lead (Pb), Chromium (Cr), Cadmium (Cd), Thallium (Tl), and Nickel (Ni) in samples of wastewater, filamentous green algae (spirogyra) and urban mosquitoes obtained from open wastewater channels in Nairobi industrial area, Kenya, was established. Industrial wastewater may contain hazardous heavy metals upon exposure. Aquatic organisms in wastewater may accumulate the toxic elements with time. Therefore, human population living in informal settlements in Nairobi industrial area risk exposure to such toxic elements. Biomonitoring using aquatic organisms can be key in metal exposure assessment. Results Pb, Cr, & Ni levels ranged from 3.08 to 15.31 µg/L while Tl, Hg, & Cd levels ranged from 0.05 to 0.12 µg/L in wastewater. Pb, Cr, Ni, & Cd levels were above WHO, Kenya & US EPA limits for wastewater but Hg was not. Metals in tap water (control) which ranged from 0.01 to 0.2 µg/L was below WHO, US EPA, & Kenya standard limits. Pb, Cr, Tl, & Ni levels in assorted field mosquitoes were 1.3 to 2.4 times higher than in assorted laboratory-reared mosquitoes. Hg & Cd concentrations in laboratory-reared mosquitoes (0.26 mg/L & 1.8 mg/L respectively) was higher than in field mosquitoes (0.048 mg/L & 0.12 mg/L respectively). Pb, Cr, Ni, & Cd levels in green filamentous algae were 110.62, 29.75, 14.45, & 0.44 mg/L respectively and above WHO limits for vegetable plants. Hg level in algae samples (0.057 mg/L) was below WHO standard limits but above Kenya & US EPA limits in vegetables. Correlations for Pb & Hg (r = 0.957; P < 0.05); Cd & Cr (r = 0.985; P < 0.05) in algae samples were noted. The metal concentrations in the samples were in the order, wastewater < mosquitoes < filamentous green algae. Conclusion Samples of wastewater, mosquitoes and filamentous green algae from open wastewater channels and immediate vicinity, in Nairobi industrial area (Kenya) contained Hg, Pb, Cr, Cd, Tl, and Ni. Urban mosquitoes and filamentous green algae can play a role of metal biomonitoring in wastewater. The possibility of urban mosquitoes transferring the heavy metals to their hosts when sucking blood should be investigated.

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Section: Methodsmentioning

confidence: 99%

Urban mosquitoes and filamentous green algae: their biomonitoring role in heavy metal pollution in open wastewater channels in Nairobi, Kenya

Kinuthia

Ngure

Kamau

2021

Preprint

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“…Mining and smelting activities in China continue to be the major contamination sources for Cd and Hg . The concentrations of Pb, Cd, Zn, and Ni in agricultural soil and food produced around the Migori gold mining area in Kenya exceed maximum allowable levels (Ngure and Kinuthia, 2020). Coal mining can be a source of Hg, Cd, Zn, and Cu contamination (Sun et al, 2019).…”

Section: Atmospheric Depositionmentioning

confidence: 99%

“…The presence of HMs in water and soil increases the risk of food-chain contamination (Saadati et al, 2020;Taghipour and Jalali, 2019). HMs are hurtful substances that are highly perseverance and non-biodegradable (Garrigues et al, 2019;Liao et al, 2016), their presence in food is a threat to human health (Massoud et al, 2019) and when consumed can accumulate in different body organs and affect their functions (Ngure and Kinuthia, 2020). HMs have their way into the food during production in metal-contaminated soil (Thakali and Macrae, 2021).…”

Section: Introductionmentioning

confidence: 99%

Heavy Metals in Food Crops: Ideal Sources and Roles of Urban Agriculture in Facilitating Their Consumption- A Review

Abdullahi¹,

Igwe²,

Dandago³

et al. 2021

FJS

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The qualities of agricultural soil and water are diminishing continuously due to the rigorous anthropogenic activities currently stocking the soil with a lot of toxic chemicals including heavy metals. Heavy metals are highly persistent and non-biodegradable, control of their contamination is very tricky to handle. Their presence in soil and water is detrimental to food crops and humans. Various sources of heavy metals contaminants and the role of urban food production on human heavy metal contamination were discussed.Heavy metals have their way into the soil and food crops through wastewater irrigation and production in contaminated soil. The habitual heavy metals contamination sources for food crops are wastewater irrigation, abuse of agrochemicals, production in the contaminated field, atmospheric deposit when foods are exposed to contaminated air, and unethical mining activities. Agricultural soil in urban and peri-urban areas are heavily contaminated with heavy metal due to various anthropogenic activities. Wastewater irrigation intensify the contamination by supplying the soil with more heavy metals. The heavy metals are passed to food during production and subsequently to humans after consumption.

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“…One part was air dried at room temperature for several days while the remaining part was lyophilized (freeze dried). Both air dried and lyophilized algae samples were ground and sieved to obtain a fine powder as described by Ngure and Kinuthia [34]. The powder was then weighed and packaged in well labeled brown small envelops to await metal analysis.…”

Section: Preparation Of Green Algae Samples For Heavy Metal Analysismentioning

confidence: 99%

Urban mosquitoes and filamentous green algae: their biomonitoring role in heavy metal pollution in open drainage channels in Nairobi industrial area, Kenya

2021

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Background Industrial wastewater is a human health hazard upon exposure. Aquatic organisms in contaminated wastewater may accumulate the toxic elements with time. Human population living in informal settlements in Nairobi industrial area risk exposure to such toxic elements. Biomonitoring using aquatic organisms in open drainage channels can be key in metal exposure assessment. Levels of Mercury (Hg), Lead (Pb), Chromium (Cr), Cadmium (Cd), Thallium (Tl), and Nickel (Ni) were established in samples of wastewater, filamentous green algae (Spirogyra) and mosquitoes obtained from open drainage channels in Nairobi industrial area, Kenya. Results Pb, Cr, & Ni levels ranged from 3.08 to 15.31 µg/l while Tl, Hg, & Cd ranged from 0.05 to 0.12 µg/l in wastewater. The Pb, Cr, Ni, & Cd levels were above WHO, Kenya & US EPA limits for wastewater but Hg was not. Pb, Cr, Tl, & Ni levels in assorted field mosquitoes were 1.3–2.4 times higher than in assorted laboratory-reared mosquitoes. Hg & Cd concentrations in laboratory-reared mosquitoes (0.26 mg/kg & 1.8 mg/kg respectively) were higher than in field mosquitoes (0.048 mg/kg & 0.12 mg/kg respectively). The levels of Pb, Cr, & Ni were distinctively higher in field mosquito samples than in wastewater samples from the same site. Pb, Cr, Ni, Cd & Hg levels in green filamentous Spirogyra algae were 110.62, 29.75, 14.45, 0.44, & 0.057 mg/kg respectively. Correlation for Pb & Hg (r (2) = 0.957; P < 0.05); Cd & Cr (r (2) = 0.985; P < 0.05) in algae samples was noted. The metal concentrations in the samples analyzed were highest in filamentous green algae and least in wastewater. Conclusion Wastewater, mosquitoes, and filamentous green algae from open drainage channels and immediate vicinity, in Nairobi industrial area (Kenya) contained Hg, Pb, Cr, Cd, Tl, and Ni. Mosquitoes in urban areas and filamentous green algae in open drainage channels can play a role of metal biomonitoring in wastewater. The potential of urban mosquitoes transferring heavy metals to human population from the contaminated wastewater should be investigated.

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Health risk implications of lead, cadmium, zinc, and nickel for consumers of food items in Migori Gold mines, Kenya

Cited by 24 publications

References 50 publications

Urban mosquitoes and filamentous green algae: their biomonitoring role in heavy metal pollution in open wastewater channels in Nairobi, Kenya

Urban mosquitoes and filamentous green algae: their biomonitoring role in heavy metal pollution in open wastewater channels in Nairobi, Kenya

Heavy Metals in Food Crops: Ideal Sources and Roles of Urban Agriculture in Facilitating Their Consumption- A Review

Urban mosquitoes and filamentous green algae: their biomonitoring role in heavy metal pollution in open drainage channels in Nairobi industrial area, Kenya

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