The Safe Water Optimization Tool (SWOT) generates evidence-based point-of-distribution free residual chlorine (FRC) targets to adjust chlorine dosing by operators and ensure water quality at point-of-consumption. To investigate SWOT effectiveness in surface waters, we conducted two before-and-after mixed-method evaluations in a Uganda refugee settlement served by piped and trucked surface water systems. We surveyed 888 users on water knowledge, attitudes, and practices; collected 2768 water samples to evaluate FRC,Escherichia coli, and disinfection by-products (DBPs) concentrations; and conducted nine key-informant interviews with system operators about SWOT implementation. After baseline data collection, SWOT chlorination targets were generated, increasing point-of-distribution FRC targets from 0.2 to 0.7-0.8 mg/L and from 0.3 to 0.9 mg/L for piped and trucked systems, respectively. At endline, household point-of-consumption FRC ≥ 0.2 mg/L increased from 23 to 35% and from 8 to 42% in the two systems. With these increases, we did not observe increased chlorinated water rejection or DBPs concentrations exceeding international guidelines. Informants reported that SWOT implementation increased knowledge and capacity and improved operations. Overall, SWOT-generated chlorination targets increased chlorine dosage, which improved household water quality in surface waters although less than previously documented with groundwater sources. Additional operator support on prechlorination water treatment processes is needed to ensure maximally effective SWOT implementation for surface water sources.
In May 2010, a team of national and international organizations was assembled to investigate children's deaths due to lead poisoning in villages in northwestern Nigeria.
OBJECTIVES
To determine the cause of the childhood lead poisoning outbreak, investigate risk factors for child mortality, and identify children aged <5 years in need of emergency chelation therapy for lead poisoning.
METHODS
We administered a cross-sectional, door-to-door questionnaire in two affected villages, collected blood from children aged 2-59 months, and soil samples from family compounds. Descriptive and bivariate analyses were performed with survey, blood-lead, and environmental data. Multivariate logistic regression techniques were used to determine risk factors for childhood mortality.
RESULTS
We surveyed 119 family compounds. One hundred eighteen of 463 (25%) children aged <5 years had died in the last year. We tested 59% (204/345) of children, aged <5 years, and all were lead poisoned (≥10 µg/dL); 97% (198/204) of children had blood-lead levels ≥45 µg/dL, the threshold for initiating chelation therapy. Gold ore was processed inside two-thirds of the family compounds surveyed. In multivariate modeling significant risk factors for death in the previous year from suspected lead poisoning included: the child's age, the mother performing ore-processing activities, community well as primary water source, and the soil-lead concentration in the compound.
CONCLUSION
The high levels of environmental contamination, percentage of children aged <5 years with elevated blood-lead levels (97%, >45 µg/dL), and incidence of convulsions among children prior to death (82%) suggest that most of the recent childhood deaths in the two surveyed villages were caused by acute lead poisoning from gold ore-processing activities. Control measures included environmental remediation, chelation therapy, public health education, and control of mining activities.