Lo et al. the 43 villages without soil/dust samples with lead levels > 400 ppm (27 ore-processing vil- lages and 16 of 16 non-ore-processing vil- lages), 23 (53%) had ≥ 1 child with a BLL ≥ 10 µg/dL and none had ≥ 1 child with a BLL ≥ 45 µg/dL. Discussion Findings. Results of this investigation dem- onstrated widespread childhood lead poison- ing and lead contamination among villages in Anka, Bukkuyum, and Maru LGAs in Zamfara State. The majority of villages sur- veyed had at least one child < 5 years of age with a BLL ≥ 10 µg/dL, regardless of ore- processing status, and children < 5 years with convulsions and death following convulsions also were reported in both ore-processing and non-ore-processing villages. However, childhood convulsions and deaths and high soil/dust-lead levels were significantly more likely to be found in villages report- ing recent gold ore processing than in other villages. Our data support the hypothesis that processing lead-rich gold ore resulted in lead-contaminated villages and homes, lead poisoning among young children, and pos- sibly convulsions and death from severe lead poisoning. Urgent interventions are required to reduce lead exposure, morbidity, and mortality in affected communities. Gold mining and lead exposure. Gold pro- duction has increased worldwide concomitant with global demand. The price of gold has increased approximately 360% from 2001 to 2010 (Swenson et al. 2011). Among develop- ing countries, small-scale gold ore process- ing and production have increasingly been adopted by rural communities. The envi- ronmental and health impacts of small-scale gold production are often overlooked. Gold mining and processing are known to cause air and water pollution from arsenic, mer- cury, and cyanide. Gold processing can also cause mercury poisoning in workers because of direct exposure to liquid or vaporized mer- cury during ore processing (Swenson et al. 2011). Although lead pollution is not com- monly associated with gold mining, studies of small-scale gold mining sites in the Migori gold belt (Kenya) have demonstrated lead, mercury, and arsenic pollution of multiple gold processing sites; recorded soil lead levels ranged from 16 to 14,999 ppm (Odumo et al. 2010; Ogala et al. 2002). A study in Ecuador demonstrated lead, manganese, and mercury pollution of river water near the surveyed small-scale gold-mining sites; approximately 40% of adults from the affected communi- ties had BLLs > 20 µg/dL (Betancourt et al. 2005). The widespread childhood lead poison- ing and lead contamination identified during our investigation illustrates the urgent need to monitor and prevent lead pollution from gold 1454 ore–processing activities, particularly among small-scale gold mining communities globally. In Zamfara State, gold mining began in the early 1900s (Nigeria Ministry of Mines and Steel Development 2010a), but our prior investigation in two affected villages showed that most families did not begin gold ore processing until 2009–2010 (Dooyema et al. 2012). Lead was not previously known to be present in this part of the country until high lead levels in gold ore from locations in Zamfara State were identified through recent exploration activities intended to identify new mining sites (Nigeria Ministry of Mines and Steel Development 2010a, 2010b). A sub- stantial number of geographically dispersed locations in Zamfara State and its neighbor- ing states were reported as sources of ore; lead content in ore from these locations remains unknown. Geologic studies are needed to sys- tematically investigate the lead content of gold ore in this region and identify sources of ore that may increase the risk of lead poisoning among miners and their families. Processing lead-rich ore inside villages leads to lead contamination. Contaminated soil and household dust are likely to be the main sources of lead exposure for children living in ore-processing villages. During this investigation we applied U.S. EPA standards established to protect children from typical soil-lead exposures in the United States to cat- egorize lead levels in the soil and household dust samples (U.S. EPA 2003). However, because of bare soil flooring, unpaved roads, and lack of vegetative cover, children in the surveyed villages are likely to interact with the soil in their environment more closely and fre- quently than do children in the United States, which may result in increased exposures at soil-lead levels below U.S. EPA thresholds (U.S. EPA 2003). Therefore, further inves- tigation to determine appropriate standards for health-protective soil-lead levels in such communities is warranted. Furthermore, although BLLs ≥ 45 µg/dL and soil-lead lev- els > 400 ppm were reported exclusively in ore-processing villages, children with BLLs ≥ 10 µg/dL were present in half of the non- ore-processing villages. Leaded gasoline was phased out in Nigeria during 2003 (United Nations Environmental Program 2010), but other potential sources of lead exposure, such as water supplies or traditional medicine, should be investigated in future studies. Recommendations. Villages with high soil- lead levels identified during this investigation should be prioritized for public health messag- ing and environmental interventions to reduce childhood lead exposure. Because gold ore processing has become an important source of income, banning villagers from conduct- ing any gold ore–processing activity would be impractical and may damage their economic viability. Instead, gold ore–processing activities should be prohibited inside villages and moved to secured locations that are inaccessible to children. Miners and persons who process ore should be educated regarding occupational precautions and protective measures to reduce the risk of harmful lead exposure for them- selves and their families. Miners should change their clothes and shoes when entering and leaving worksites to reduce the likelihood of carrying lead-contaminated dust home. Gold ore–processing activities within villages should be monitored and prohibited to prevent fur- ther contamination. Radio programs, dramas, and community gatherings are being used to educate villagers about the health effects of lead, sources of lead, and ways to reduce lead exposure in their homes, villages, and work- sites. Both ore-processing villages and non- ore-processing villages should receive these messages given the rapid proliferation of gold ore processing in this region. Villages with high soil lead levels should also be prioritized for environmental interven- tions. Assessments should include measure- ment of lead exposure in all public areas and all households in the village, and environmen- tal remediation efforts should include removal of lead-contaminated ore-processing materials, surface soil, and household dust, and replacing removed surface soil with clean soil. During June 2010–March 2011, such environmen- tal remediation was successfully conducted in seven villages (Blacksmith Institute 2011). Case identification and treatment for lead poisoning should first be extended to villages in which a child with a BLL ≥ 45 µg/dL was identified, followed by villages with child- hood lead poisoning, lead contamination, or both. Children with frank lead poisoning will require long-term follow-up and support. Health care providers in this region need to be trained to diagnose and treat lead poisoning, and medical treatment should be coordinated with environmental interventions because chelation therapy alone will be ineffective if children remain in contaminated homes. Even with remediation efforts and medi- cal treatment, recontamination and recurrent lead poisoning can occur if the source of lead exposure (e.g., ore processing) continues to be present or is reintroduced in villages. State and local authorities should develop and sustain the capacity to institute blood and environ- mental lead surveillance to identify new cases and affected villages, and monitor BLLs and environmental lead contamination during and after implementation of control measures. Limitations. Villages of interest were identified through a chain-referral sampling process that might not have captured all vil- lages involved with gold ore processing in Zamfara State, and hard-to-reach or inacces- sible villages of interest were not investigated. ovlume 120 | number 10 | October 2012 • Environmental Health Perspectives