Table 5. Disease burden associated with lead contamination of water from consumer taps, two water supply schemes combined, Nigeria, 2010–2011.

Consumer	Age rangea (years)	Fraction of all consumers (CF)	Health outcome				Estimated disease burden (DALYs per person per year [x 10−3])
			Type	RR29	Probability		Individual health outcome	All health outcomes
All	0–4 and 15–54	0.6877	All	NA	NA		NA	1.6
Child	0–4	0.1815	Mild mental retardation	NA	0.18 × 10−3		0.0022	NA
Adult female	15–54	0.2341	Ischaemic heart disease	1.024	8.9 × 10−3		0.11	NA
			Stroke	1.032	0.012		0.15	NA
			Hypertensive disease	1.063	0.023		0.29	NA
			Other cardiac disease	1.007	2.6 × 10−3		0.032	NA
Adult male	15–54	0.2721	Ischaemic heart disease	1.038	0.014		0.17	NA
			Stroke	1.052	0.020		0.25	NA
			Hypertensive disease	1.101	0.037		0.46	NA
			Other cardiac disease	1.034	0.013		0.16	NA

DALY, disability-adjusted life year; NA, not applicable; RR, relative risk.

^a Mild mental retardation is largely irreversible and is considered to occur only in the first year of life. The burden in children aged between 1 and 14 years is attributed to events in the first year. Since the population data available were for the 0–4 year age group, we assumed that the probability of mild mental retardation for infants aged under 1 year was one fifth that for the 0–4 year age group (Equation 12).²⁹