38 of 55 (69%) villages in Maru LGA. The 40 villages not visited were either inacces- sible because of poor road conditions (13 vil- lages) or were too remote to reach in 1 day (27 villages). Among the 74 villages visited, 70 (95%) completed the survey and were included for analysis. Among these 70 villages, the estimated median population was 1,800/village (range, 150–13,000), and the estimated median number of family compounds was 100/vil- lage (range: 11–1,000). The estimated median number of children < 5 years of age with con- vulsions during the previous 12 months was 19/village (range, 0–200), and the median number of children who had died follow- ing convulsions was 5/village (range, 0–100). Venous blood was collected from 314 chil- dren in the 70 villages (median/village 5; range, 1–8). The median age of the children sampled was 3 years (range, 6 months–4 years), and BLLs among the sampled chil- dren ranged from < 3.3 to > 65 µg/dL). Lead levels in soil/dust samples collected from the 70 villages ranged from undetectable to 87,293 ppm. Fifty-four (77%) of the 70 villages reported participation in any gold ore– processing activity during the previous 12 months and thus were classified as ore- processing villages. The most common gold ore–processing activities were breaking rocks (69%), washing (70%), and drying (69%) (Table 1). Ore-processing villages identified 84 sources of ore that were geographically dispersed among the three surveyed LGAs in Zamfara state, and in Kebbi, Niger, and Kaduna states (data not shown). Villages with childhood lead poisoning and lead contamination were widely dis- tributed in the three LGAs (Figures 2 and 3). Ore-processing villages were more likely than the other villages to report that ≥ 1 child < 5 years of age had convulsions during the previous 12 months (85% vs. 50%, p = 0.003) and that ≥ 1 child had died following con- vulsions (74% vs. 44%, p = 0.02) (Table 2). Ore-processing villages also were more likely to have ≥ 1 child with a BLL ≥ 10 µg/dL (68% vs. 50%, p = 0.17), and children with a BLL ≥ 45 µg/dL were identified in ore- processing villages only (8 of 54 villages vs. 0 of 16, p = 0.22). Half of the ore-processing Table 1. Gold ore–processing activities in villages of interest during the previous 12 months [n (%)]. Activity Breaking rocks Grinding Washing Drying Amalgamation and melting ≥ 1 of the above activities Environmental Health Perspectives • volume 120 | number 10 | October 2012 Childhood lead poisoning in Zamfara State, Nigeria villages had ≥ 1 soil/dust sample with a lead level > 400 ppm compared with none of the other villages (p < 0.001). Twenty ore- processing villages (37%) had ≥ 1 soil/dust sample with a lead level > 1,200 ppm. Fifty (71%) villages had childhood lead poison- ing, lead contamination, or both, including 42 of 54 ore-processing villages and 8 of 16 non-ore-processing villages (OR = 3.5; 95% CI: 1.1, 11.3; p = 0.03). Among the 27 ore- processing villages with soil/dust lead contam- ination, 22 (81%) had ≥ 1 child with a BLL ≥ 10 µg/dL and 8 (30%) had ≥ 1 child with a BLL ≥ 45 µg/dL. In comparison, among Bukkuyum LGA BLL ≥ 45 µg/dL BLL 10–44 µg/dL BLL < 10 µg/dL Figure 2. Distribution of surveyed villages by BLLs. Bukkuyum LGA Soil-lead level ≥ 1,200 ppm Soil-lead level 401–1,200 ppm Soil-lead level ≤ 400 ppm Anka LGA Maru LGA Anka LGA Maru LGA Maru LGA Maru LGA N N 0 10 20 Kilometers 0 10 20 Kilometers Figure 3. Distribution of surveyed villages by soil lead levels. Table 2. Comparisons of characteristics between ore-processing villages and non-ore-processing villages. Participating villages (n = 70) 48 (69) 29 (41) 49 (70) 48 (69) 43 (61) 54 (77) Characteristic ≥ 1 child < 5 years of age who had convulsions during the previous 12 months ≥ 1 child < 5 years of age who had convulsions and died during the previous 12 months ≥ 1 child < 5 years of age with a BLL ≥ 10 µg/dL ≥ 1 child < 5 years of age with a BLL ≥ 45 µg/dL ≥ 1 soil/dust sample with a lead level > 400 ppm ≥ 1 soil/dust sample with a lead level > 1,200 ppm ≥ 1 child < 5 years of age with a BLL ≥ 10 µg/dL or ≥ 1 soil/dust sample with a lead level > 400 ppm Ore-processing villages Yes (n = 54) No (n = 16) n (%) n (%) 46 (85) 8 (50) 40 (74) 37 (68) 8 (15) 27 (50) 20 (37) 42 (78) 7 (44) 8 (50) 0 (0) 0 (0) 0 (0) 8 (50) OR (95% CI) 5.8 (1.7, 19.8) 3.7 (1.2, 11.7) 2.2 (0.7, 6.8) undefined undefined undefined 3.5 (1.1, 11.3) p-Value 0.003 0.02 0.17 0.22 < 0.001 0.003 0.03 1453