Lead Poisoning in Zamfara State Nigeria: Effects on Environmental Health

Abstract

The people of Zamfara State, Nigeria are primarily farmers and herders. Villagers notably in Anka and Bukkuyum engage in artisanal gold mining practices. The processing of lead-rich ore to obtain gold resulted in extensive dispersal of lead dust causing widespread ingestion and inhalation of lead particles. Medecin Sans Frontieres (MSF) in March 2010 reported a high number of deaths among children mostly in the age range of 0–5 years. Field investigations found excessive of lead in surface water (≤ 200 μg/l0), soil (≤ 600 ppm) and mercury levels in air (≤ 24 micrograms per cubic meter). The methodology in this study comprised of extensive review of investigation results in literature from 2010 to present. The first environmental health report confirmed that the primary source of lead exposure is soil ingestion. Clinical report found that blood lead levels of affected children were unprecedented (mean = 119 μm/dl). The lead crisis covers at least 47 villages, affecting more than 30,000 residents. Consequently, crops for humans and pasture for grazing animals that grow on the contaminated soil are considered toxic for consumption. With coordinated response by agencies and governments aided by funding from UN CERF, lead levels have dropped sharply from over 40% during the peak of mining activities in 2010 to 1% in 2011. Sustainable changes to mining activities, proper hygiene measures and adherence to Mining Laws are hereby recommended.

1. Introduction

Zamfara State is located in Northwestern Nigeria at latitudes 10^o5000 – 13^o3800N, longitudes 4^o1600 – 7^o1300E and altitude of 451.00 meters above sea level [1]. The State (Zamfara) shares borders with the Republic of Niger to the Northeast, Kaduna State to the Southeast, Katsina State to the East, Sokoto and Kebbi States to the North and Niger State to the Southwest. Zamfara State covers a land mass of 39,762 square kilometers and is inhabited by an estimated total population of 3,582,912 people, over 80 percent of whom are engaged in various forms of agriculture [2].

Zamfara State is characterized by a tropical warm climate with relatively higher temperatures up to 38^o C from March to June, shorter period of precipitation from July to September and a period of relatively cold, dusty and dry Harmattan from December to February [3]. Major agricultural products from the state include millet, guinea corn, maize, rice, ground nuts, cotton, tobacco and beans (mostly, cowpea). These crops are grown in all fourteen (14) Local Government Areas (LGAs) of the state namely, Anka, Bakura, Birnin Magaji, Bukkuyum, Bungudu, Gumi, Gusau, Kaura Namoda, Maradun, Maru, Shinkafi, Talata Mafara, Tsafe and Zurmi [4].

Being an agricultural community, most villagers in Zamfara State rely on farming to earn a living. However, the region is also richly endowed with many different types of solid minerals including gold. With a recent global rise in the prices of gold, many villagers have started mining gold to earn more money [5]. Gold mining trade in Zamfara communities is estimated to have commenced in 2006 or even much earlier. It has been observed that the communities engaged in many unsafe mining practices that would expose children, adults and animals to harmful levels of lead [6]. In the conduct of their mining operations, most villagers do not wear any personal protective equipment while working with the lead ore. They would return home with lead dust on their clothing, shoes and mining implements. Similarly, when they brought lead ore inside their homes to extract gold, the lead dust would spread over many areas within and around the compound, elder children often helped to grind the lead ore to extract gold while the younger children would play around within the lead-contaminated compounds. These activities and behaviors expose the occupants to high levels of lead dust, which could be injurious to their health [7].

2. The place of occurrence of the lead poisoning crisis in Zamfara state

In early 2010, the first presumed clue to environmental pollution (though apparently unclear to the local residents) began to emerge in the region. The report indicated a gradual reduction in numbers and subsequently, complete disappearance of duck population from the gold mining areas, which later became manifest throughout the region. These manifestations have been termed as the Sentinels (warning signs) of environmental hazards [6]. In March 2010, Medecins Sans Frontieres (MSF-Holland) that is, Doctors without borders discovered an unprecedented epidemic of lead poisoning in the region (Zamfara State) first in three Local Government Areas namely, Anka, Bukkuyum and Maru. An estimated 400 to 500 children were reported to have died from lead absorption, associated with the artisanal gold mining and processing in the area [7]. Investigations of other villages in the region revealed that lead poisoning was widespread in the State. Thousands of children had dangerous levels of lead in their blood and hundreds of children and animals had died of lead poisoning. It has been reported to be the largest known outbreak of lead poisoning in history [5].

High lead concentrations from unsafe artisanal gold mining and processing practices continued to cause lead poisoning mortality in younger children and morbidity in older populations [8]. The primary pathway of exposure for young children is through soil ingestion. Consequently, even if the exposure to lead had to stop now, the children already having lead poisoning would require years of expensive medical treatment [9]. Investigation reports on groundwater pollution in the area have shown that lead pollution remained confined to areas (wells and ponds) where mining and processing of gold from lead ore had taken place and had not spread through the groundwater aquifer [2]. In some drinking wells, concentrations of lead 10 to 15 times greater than the WHO recommended limit of 10 μg/L have been found. Also, reports on surface water sources (ponds, rivers and lakes) in the mining areas showed higher concentrations of lead up to more than 10,000 μg/dl, which is 10 times greater than the exposure limit recommended by the Food and Agricultural Organization (FAO) of the United Nations (UN) for livestock [10].

Investigations on soil generally showed concentrations up to 8 percent higher in locations closer to drinking water wells and other surface water sources. This was suspected to have been caused by lead dust deposition and soil run-off from sites where lead-contaminated ore was being processed. Gold processing was done by repeated washing of the lead ore using metal head pans by decantation process to extract gold. The contaminated water and soil containing the lead ore were continuously spread all over surfaces within the residential compounds and surrounding areas [5]. At ore processing locations, incidental inhalation and ingestion of soil are a common source of exposure particularly for infants and toddlers, ingestion commonly occurs via hand-to-mouth behavior and eating food with contaminated hands [2]. Reports indicated that lead poisoning incidence from illegal mining activities in Zamfara State from 2010 to 2011 had led to the death of at least 735 children, mostly aged 0 to 5 years, and has left thousands of others ill with the lead poisoning [11].

3. Methodology

The methodology in this study comprised of extensive review of investigation results in literature from 2010 to the present. Information gathered primarily contains but is not limited to published reports by the agencies in the Zamfara lead poisoning intervention. Secondary sources of information include published reports of discrete investigations on lead poisoning/contamination in Zamfara State as well as some other reviews on the subject matter. The first environmental health investigation report published by CDC in early 2010 confirmed that the primary source of lead exposure is soil ingestion but there was insufficient information on the quantities of lead in drinking water (groundwater and surface water). Likewise, the levels of lead in soil and mercury in air were not determined at the time. A report by JEU [2] revealed the lead concentrations in soil, surface and groundwater as well as mercury levels in the air.

A clinical investigation report that found the blood lead levels of affected children was conducted in late 2010 and covered wide areas of the state and targeted most if not all affected persons. Major events include data gathering and reporting on environmental and clinical investigations as reported from the sources of investigation. Events were carefully followed and reported with their originality through literature and oral communication with some stakeholders in the mission. Other information was originally sourced from the community leaders through visits, personal communications and other means of contact after seeking their permission. Information gathered includes the report by national and international agencies that participated in the mission. These include MSF, CDC, WHO, UNICEF, UNEP, OCHA, NCDC, TI, NWRI, etc.

4. Results of the lead poisoning investigations in Zamfara state

The processing of lead-rich ore to obtain gold has resulted in extensive dispersal of lead dust in the affected villages causing widespread ingestion and inhalation of fine lead particles among the residents. Medecin Sans Frontieres (MSF) in March 2010 reported a high number of deaths among children mostly in the age range of 0–5 years from these localities. Field investigations conducted by multiple agencies in collaboration with Nigerian and Zamfara State Governments found excessive levels of lead in surface water (≤ 200 μg/l0, soil (≤ 600 ppm) and mercury levels in air (≤ 24 micrograms per cubic metre).

The first environmental health investigation report published by CDC prior to the lead poisoning investigation mission in 2010 confirmed that the primary source of lead exposure is soil ingestion but there was insufficient information on the quantities of lead in drinking water (groundwater and surface water). Likewise, the levels of lead in soil and mercury in air were not determined at the time. Report by JEU [2] revealed the lead concentrations in soil, surface and groundwater as well as mercury levels in air. Clinical investigation report [7] found that blood lead levels of affected children were unprecedented (mean = 119 μm/dl). Further investigation reports revealed that the lead pollution crisis covers at least 47 villages, affecting more than 30,000 residents. Consequently, food crops for humans and pasture for grazing animals that grow on the contaminated soil are considered toxic for consumption.

5. Why and how lead poisoning occurs in Zamfara state

Zamfara State, Nigeria has since at least early 2010 begun to witness serious cases of heavy metals poisoning, which translated into a huge number of deaths in human populations particularly children aged 0 to 5 years. There is also the fear that tones of heavy metals (mostly lead) released due to unsafe gold mining practices in many parts of the State (Zamfara) may have the tendency to accumulate and concentrate along the food chain as they (heavy metals) move from one trophic level to the next. This would in turn affect not only the physical or abiotic component of the environment (comprising of soil, water and air) but also the biological or biotic component (comprising of humans, other animals and plants). Consequently, the consumption of crops grown on lead-contaminated fields and animals fed on pasture from these mining areas will constitute a potential risk for ailments associated with heavy metals poisoning. In addition, the chronic effects of poisoning from the metal pollutants on the apparently healthy surviving populations can translate into serious clinical problems that are never imagined [2, 10, 12, 13, 14].

Lead is a naturally occurring metal in soil [15]. It was however unusual to find such high levels of lead in these communities [5]. Apart from the seven villages in Zamfara State that have undergone environmental remediation from June 2010 to March 2011, at least 43 additional villages in the State were reported to have confirmed cases of lead poisoning with the affected children having blood lead concentration greater than 45 μg/dL and therefore require chelating therapy [2]. In Bagega town (Anka LGA), the level of pollution was very alarming. Many family compounds and community areas in the town had soil lead concentrations above 1000 ppm (in the USA, 400 ppm is the blood lead concentration limit, where there are children), and an estimated number of 1500 children were reported to have been poisoned with lead in Bagega alone [7].

Mining had become an important source of income for the villagers in the area. It had become almost impossible for the villagers to stop mining completely [6]. Having realized a lead poisoning outbreak of huge magnitude among children in Zamfara State, the Nigerian authorities requested the World Health Organization (WHO) to provide further technical and financial assistance to resolve the problem and prevent future reoccurrences. A team of experts comprising three epidemiologists, a chemical toxicologist, a pediatrician, an environmental health expert and a laboratory specialist arrived in Zamfara State in June 2010 to investigate the lead poisoning situation [7]. While the response team was busy investigating the lead poisoning outbreak, Blacksmith Institute (BI) sent a team from TerraGraphics Engineering Incorporated (TG) to conduct an environmental assessment (physical) of the situation. The two teams worked together with officials of the Federal Government of Nigeria and Zamfara State authorities, WHO country office in Nigeria and MSF. In their report dated 7th July, 2010, members of both teams have confirmed a high degree of environmental lead contamination from gold mining activities in five additional villages in the state namely Tungar–daji, Abare, Duza, Sunke (Anka LGA) and Tungar–guru (Bukkuyum LGA) [8].

High lead concentrations from unsafe artisanal gold mining and processing practices continued to cause lead poisoning mortality in younger children and morbidity in older populations [8]. The primary pathway of exposure for young children is through soil ingestion. Consequently, even if the exposure to lead had to stop now, the children already having lead poisoning would require years of expensive medical treatment [9]. Investigation reports on groundwater pollution in the area have shown that lead pollution remained confined to areas (wells and ponds) where mining and processing of gold from lead ore had taken place and had not spread through the ground water aquifer [2]. In some drinking wells, concentrations of lead 10 to 15 times greater than the WHO recommended limit of 10 μg/L have been found. Also, reports on surface water sources (ponds, rivers and lakes) in the mining areas showed higher concentrations of lead up to more than 10,000 μg/dl, which is 10 times greater than the exposure limit recommended by the Food and Agricultural Organization (FAO) of the United Nations (UN) for livestock [10].

Investigations on soil generally showed concentrations up to 8 percent higher in locations closer to drinking water wells and other surface water sources. This was suspected to have been caused by lead dust deposition and soil run-off from sites where lead-contaminated ore was being processed. Gold processing was done by repeated washing of the lead ore using metal head pans by decantation process to extract gold. The contaminated water and soil containing the lead ore were continuously spread all over surfaces within the residential compounds and surrounding areas [5]. At ore processing locations, incidental inhalation and ingestion of soil are a common source of exposure particularly for infants and toddlers, ingestion commonly occurs via hand-to-mouth behavior and eating food with contaminated hands [2]. Reports indicated that lead poisoning incidence from illegal mining activities in Zamfara State from 2010 to 2011 had led to the death of at least 735 children, mostly aged 0 to 5 years, and has left thousands of others ill with the lead poisoning [11, 16].

6. Lead in drinking water

Recent scientific findings suggest that all exposures to lead should be avoided as there is no safe exposure concentration for lead. The lower concentration levels of lead in water (<10–13 μg/l) obtained in the mining area may be disguised when compared to that in soil because children who drink contaminated water are also exposed to lead-contaminated dust and/or get exposure through hand to mouth behavior, a bigger impact of lead poisoning may arise. Therefore even the lower concentrations found in drinking water wells in most contaminated villages in Zamfara State might be a risk, especially for younger children aged 0 to 5 years. However, since results from the investigations of Zamfara lead poisoning reported no contamination in boreholes, drinking water from boreholes might be considered a safe alternative for people in the villages [17].

7. Lead in surface water

At many points in the region where villagers used surface water sources (i.e. ponds, rivers, streams, lakes and pools), for the processing of lead-contaminated ore to obtain gold, the concentration levels of lead found in surface water bodies were mostly greater than 1000 μg/l. This concentration is said to be ten times higher than the exposure limit set by the FAO for livestock. Consequently, since livestock in the area usually drink from surface water sources, this could have been the reason for the frequent cases of illness and death of livestock often reported by the villagers. Consequently, the slaughter and consumption of any lead-poisoned animal would constitute an important exposure route for humans [17].

8. Lead in soil

Some recent reports on the concentrations of lead in soils in the affected villages showed three levels of contamination according to the locations. Higher concentrations of up to 8 percent (80 mg/kg) were obtained in locations close to surface water sources, as well as some drinking water wells. At ore processing locations, much higher lead concentrations have been reported. For example, in lead poisoning instances involving younger children and toddlers, concentrations above 1000 ppm have been reported due to incidental ingestion of soil. In some extreme cases, concentrations as high as 60,000 ppm have been reported during visits to highly polluted villages prior to their remediation. However, in many places away from the ore processing locations, much lower concentrations have been reported, suggesting a human factor in the dispersion of lead [5].

9. Lead in air

The grinding of lead ore into fine particles to extract gold has resulted in extensive dispersal of lead dust within and outside the family compounds. This unsafe gold mining practice resulted in massive environmental contamination in the affected villages of Zamfara state. Ingestion and inhalation of the fine lead particles was reported to be the major reason for high blood lead levels (BLLs) in the bodies of victims of lead poisoning. People are often exposed to lead from contact with very fine soil particles carried into houses as airborne dust or on shoes, clothing or pets. Lead from airborne sources is usually taken into the body by inhalation (or breathing). Exposure to airborne lead may result from eating garden produce grown in or near contaminated soil. Contaminated lead dust may settle on edible leaves and fruits [18].

10. Symptoms and effects of lead poisoning in Zamfara state

Prior to the Zamfara lead poisoning outbreak in 2010, there was no official report of children being exposed to lead dust from the gold mining activities already prevailing in the area [7]. The presence of fewer ducks populations was noticed by the local residents in the area during the first quarter of the year 2010, but no one thought it was important at the time. Public health officials later received reports that children became ill with unknown diseases and were suffering from vomiting, abdominal pain, headaches and seizures and many of them had died. Investigations carried out by a team of experts in the affected villages in May 2010, revealed that lead poisoning outbreak was widespread in the area. Thousands of children had dangerous levels of lead in their blood and many animals died from lead poisoning [6].

Investigations revealed alarming levels of lead concentrations in the environment. Lead concentrations in soil around the residential compounds have reached over 100,000 ppm. This is extreme over the concentration limit of 400 ppm for residential areas applicable in the USA and France. Similarly, the mean blood lead level concentration of 119 μm/dl found in more than 100 children diagnosed with severe lead poisoning in Dareta and Yargalma villages is alarming considering that 10 μg/dL blood lead level is associated with impaired neurological development in young children. Reports from other villages in the region revealed that lead poisoning was widespread in the State. Thousands of children had dangerous levels of lead in their blood and hundreds of children and animals had died of lead poisoning. This was reported to be the largest known outbreak of lead poisoning in history [5].

High lead concentrations from unsafe artisanal gold mining and processing practices continued to cause lead poisoning mortality in younger children and morbidity in older populations [8]. The primary pathway of exposure for young children is through soil ingestion. Consequently, even if the exposure to lead had to stop now, the children already having lead poisoning would require years of expensive medical treatment [9]. Investigation reports on groundwater pollution in the area have shown that lead pollution remained confined to areas (wells and ponds) where mining and processing of gold from lead ore had taken place and had not spread through the groundwater aquifer [2]. In some drinking wells, concentrations of lead 10 to 15 times greater than the WHO recommended limit of 10 μg/L have been found. Also, reports on surface water sources (ponds, rivers and lakes) in the mining areas showed higher concentrations of lead up to more than 10,000 μg/dl, which is 10 times greater than the exposure limit recommended by Food and Agricultural Organization (FAO) of the United Nations (UN) for livestock [10].

Investigations on soil generally showed concentrations up to 8 percent higher in locations closer to drinking water wells and other surface water sources. This was suspected to have been caused by lead dust deposition and soil run-off from sites where lead-contaminated ore was being processed. Gold processing was done by repeated washing of the lead ore using metal head pans by decantation process to extract gold. The contaminated water and soil containing the lead ore were continuously spread all over surfaces within the residential compounds and surrounding areas [5]. At ore processing locations, incidental inhalation and ingestion of soil are a common source of exposure particularly for infants and toddlers, ingestion commonly occurs via hand-to-mouth behavior and eating food with contaminated hands [2].

The persistent lead poisoning emergency in Zamfara State could not be resolved easily. The remediation process was a challenging and time-consuming task, involving excavation of all the contaminated soils and replacing same with clean ones to bring down the lead toxicity levels [19]. Many children affected by lead poisoning had to wait for their family compounds to be cleaned before they could start the treatment and some will require chelation for many months. A further challenge remains the purchase of sufficient chelating agents: these are expensive drugs that are not available as generics [8].

11. Environmental and clinical responses to the lead poisoning situation

Following the realization of mass acute lead poisoning in Zamfara State, environmental and clinical response approaches have been developed to address the situation [7]. The Nigerian and Zamfara State Governments, local emirates, and agencies including the CDC, MSF, WHO, TerraGraphics Engineering Incorporated (TI) the Artisanal Gold Council (AGC) and other partners were working together to secure funds to establish a holistic, sustainable solution to this tragedy [7].

12. Environmental approach

A number of environmental activities were carried out to effect decontamination of the affected villages. The Zamfara State Ministry of Environment and Solid Minerals (ZMoE) with technical assistance from the Blacksmith Institute (BI) of New York and TerraGraphics Environmental Engineering (TG) have helped to secure a clean environment in the identified seven contaminated villages and 430 compounds, which commenced from June 2010 to March 2011 [19]. The remediation process includes identification of contaminated areas in the affected villages, removal of all contaminated soil, its deposition in secure landfill sites and replacement with clean soil [6].

The World Health Organization and multiple partners have been assisting Zamfara State and Federal Authorities in Nigeria to prevent further environmental contamination with lead. Measures employed in the decontamination process include relocation of ore processing activities and storage of ore materials away from the villages, adoption of new processing methods that will reduce the emission and dispersal of lead dust, as well as hygienic measures such as removing contaminated clothes, socks and shoes and washing same before returning home after every mining session [7].

Highly contaminated wells where lead concentrations were significantly higher (2 to 3 times more) than the limit set by WHO for drinking water were directed to be closed immediately after the installation of boreholes for safer alternative drinking water. The closed wells were then integrated into the overall remediation plan. For all wells without safety walls in areas identified with vulnerability to lead contamination, concrete safety walls were earmarked for construction around all drinking water wells. This was done to prevent possible run-off of potentially lead-contaminated soil into these drinking water sources, including the newly remediated ones. The recommendation was also made by the Joint UNEP/OCHA Environment Unit [2] for the federal, state and local authorities to prevent further ore processing activities anywhere around the sources of drinking water for humans and livestock.

13. Clinical approach

Medecins Sans Fronteres (MSF) was the first agency to have discovered an unprecedented mass epidemic of lead poisoning in Zamfara State, Nigeria in March, 2010. The Center for Disease Control (CDC) and multiple partners in the health sector from within and outside Nigeria assisted Zamfara State Government in environmental health investigation and subsequently in emergency response to the health crisis [6]. Medecins Sans Frontieres built clinics in the affected villages and provided treatment for the poisoned children [8]. Over 2000 children under the age of five years were made available for treatment in the MSF clinics from the seven contaminated villages, where remediation process of the lead pollution was commenced in June, 2010 and completed in March 2011 [10].

The emergency response to the Zamfara State mass lead poisoning attracted multiple agencies from within and outside Nigeria. These agencies worked together in partnership with National and Zamfara State authorities to resolve the lead poisoning crisis. The leadership of local communities had been involved in the entire process with their representation by the community leaders, district heads and emirs [7]. The multidisciplinary agencies involved in the mission had members drawn from different nationalities and diverse areas of professionalism related to health issues and lead pollution control processes. The agencies include WHO, the UN agencies: the United Nations Children Fund (UNICEF), United Nations Development Program (UNDP), United Nations Environment Program (UNEP), UNEP Office for the Coordination of Humanitarian Affairs (OCHA), UNEP Joint Environment Unit (JEU), as well as MSF, United States Centers for Disease Control (US CDC), the Blacksmith Institute (BI), TerraGraphics Environmental Engineering Incorporated (TG) and the Artisanal Gold Council (AGC) [5].

14. UN CERF supported and coordinated activities of multiple agencies

The UN CERF had provided funding of US$1.9 million to WHO and UNICEF to support the coordinated efforts of multiple agencies in combating the epidemic of lead poisoning in Zamfara State [20]. The first two out of seven decontaminated villages (Dareta and Yargalma) have been cleaned before receipt of the funding from the UN CERF. The cleaning was conducted by the Blacksmith Institute Incorporated with the support of the Zamfara State authorities [2]. Cleaning of the other five villages (Tungar-daji, Abare, Duza, Sunke and Tungar-guru), as well as other activities earmarked in this mission, had to wait for the funding from UN CERF.

World Health Organization working with its UN partners has succeeded in securing the funding from the UN CERF to deal with the lead poisoning situation. The fund from the UN CERF has supported a series of activities towards the successes achieved through coordinated efforts of the multiple agencies for a clean, healthy environment and healthy population in Zamfara State [7]. Most achievements recorded with support from the funds include the following:-

1. Completion of remediation process of seven villages contaminated with lead in Zamfara State.

2. Conduct advocacy activities with community leaders, state and federal authorities:- Social mobilization and community awareness activities have been stepped up to educate members of local communities on the hazards of lead poisoning and ways to reduce lead exposure through safer mining and gold processing activities.

3. Training of doctors, nursing and laboratory staff on diagnosis and treatment of lead poisoning at designated health centers in Gusau, Zamfara State capital.

4. Establishment of the surveillance system for early detection of lead poisoning in Zamfara state.

5. Coordination of all partners involved in the emergency response activities.

6. Provision of three-handed X-ray fluorescence devices for rapid measurement of lead contaminations in the soil.

7. Provision of four (4) point-of-care analyzers and their kits for the rapid measurement of blood lead concentrations.

8. Graphite furnace absorption spectrometer, ancillary equipment, reagents and technical advice have been provided for the establishment of a reference laboratory for treatment of lead poisoning.

9. Provision of antidotal agents for the treatment of lead poisoning in Zamfara State.

10. Furthermore, TerraGraphics Environmental Engineering has provided training on assessment and remediation procedures, so they can be continued by local agencies. This effort has helped to facilitate effectiveness of the continued chelation therapy by MSF for lead-poisoned children in the contaminated villages.

The interventions so far have helped to prevent many deaths and thousands of children who were exposed to lead poisoning have been treated. Other children affected with lead continued receiving treatment and contaminated soil continued to be removed from the remaining villages and was replaced with clean soil [5]. With the combine effects of removal from lead exposure (environmental approach) as well as chelating and other supportive therapy (clinical approach), the mortality rate among lead-poisoned children in the seven remediated villages in Zamfara State has dropped from about 40 percent in 2010 to 1 percent in 2011 [7].

Following the coordinated effort of multiple agencies, the Zamfara State Government, and the Federal Government of Nigeria, much success has been achieved in the control of lead poisoning in the State. With the conventional remediation activities carried out, lead poisoning levels in the state is currently very minimal. Many lives have been saved and the environment cleaned within a short span of time. The mission has been a successful one. The continued presence of MSF in the region entails a follow-up to detect any possible resurgence. Our work in the region is currently battling with cholera, measles and other outbreaks as well as malnutrition issues. Most patients in our clinics and those in their homes require proper nutrition as a balanced diet is hard to come by. Most parents in the localities cannot afford it or do not care about it. It has been reported that the poor baseline nutritional status of children in the region is a major contributing factor to how severely they are affected by lead poisoning [8].

15. Conclusion

A significant drop in mortality rate due to lead poisoning (from 43 percent in 2010 to 1 percent in 2011 among exposed children (0 to 5 years) has been achieved in the state. Gold mining, being an additional source of income and means of livelihood among the villagers was difficult if not impossible to stop. Sustained changes to mining practices are therefore required to prevent further environmental contamination with lead. Efforts in this direction included relocation of ore processing activities, storage of ore materials and working implements away from villages, adoption of safer ore processing methods that produce less ore dust; as well as proper hygiene measures such as removing contaminated clothes, socks, shoes and washing them before returning home after work.

16. Recommendations

Recommendations from this study include the following:-

1. Active participation by public, private and community members to ensure full isolation of mining activities and facilities from residential, community and farm areas.

2. The Mineral Mining Act 2007 should be properly enforced.

3. Maintenance of proper hygiene habits during and after mining activities.

4. Model indigenous plant species for sustainable phytoremediation of metal-contaminated environment may be identified and selected for propagation at strategic locations.

Acknowledgments

The author acknowledges the immense contributions of a number of people and organizations, without the support of whom this work would not have been possible. These include:-

• My workplace: Usmanu Danfodiyo University, Sokoto, Nigeria, under the good leadership of Professor Lawal Suleiman Bilbis (The Vice Chancellor).

• My two Heads of Department: Professor Adamu Aliyu Aliero (Plant Science Department) and Professor Muhammad Mahe Yahaya (Biology Department), Usmanu Danfodiyo University, Sokoto, Nigeria.

• His Royal Highness, The Emir of Anka, Alhaji (Dr.) Attahiru Muhammad Ahmad CON.

• Alhaji Zubairu Muhammad Anka (Sarkin Baura of Gima Village), Anka Local Government Area, Zamfara State.

• Other community Leaders in Anka and Bukkuyum Local Government Areas, Zamfara State.

• Office Assistants and Field Workers of Lead Poisoning Intervention in Anka and Bukkuyum.

• Field Staff of multiple agencies involved in the Zamfara State Lead Poisoning Intervention, Zamfara State Ministry of Health, Federal Ministry of Health, Anka and Bukkuyum LGAs.

Conflict of interest

There is no conflict of interest issue with the coauthors in my previous publication on Lead Contamination in Zamfara State, Nigeria. That article titled, Environmental Effect of Lead Contamination on Mining Communities in Zamfara State, Nigeria - A Review, was a collaborative paper that I authored and invited them for additional inputs, suggestions and criticisms. We did it amicably in the year 2020 during the COVID-19 pandemic, when we were both less busy. The coauthors of that article are currently busy with their individual pursuits in their chosen areas of engagement. I hereby assure the audience that my relationship with each one of them is cordial and we both wish each other well. I very much appreciate each one of them for their complement to me on this project.