




































In ternationa l
Scholars
Journa ls

 

African Journal of Environmental Economics and Management ISSN 2375-0707 Vol. 7 (1), pp. 001-010, 
January, 2019. Available online at www.internationalscholarsjournals.org © International Scholars Journals 

 

Author(s) retain the copyright of this article. 
 
 

 

Full Length Research Paper 

 

The cost of environmental lead (Pb) poisoning 

in Nigeria 

 
Oladele A. Ogunseitan* and Timothy R. Smith 

 
Program in Public Health, College of Health Sciences, University of California, Irvine, CA 92697-7070 USA. 

 
Accepted 17 October, 2018 

 
The pervasiveness of human health impacts and ecosystem effects of lead (Pb) is not controversial, but there 
are serious arguments about the pace at which Pb should be eliminated from consumer products. Presumably, 
these arguments can be resolved by converting costs and benefits of Pb use to similar units, a notorious 
methodological challenge for health impacts in developing countries. To estimate the costs of Pb poisoning 
attributable to petrochemicals in Nigeria, we conducted a meta-analysis of measured blood lead levels (BLL) 
and we used published Relative Risk values for disease categories to estimate the proportion of overall disease 
burden attributable to Pb. We modeled the health costs of Pb exposure and we compared this to the cost of 
banning Pb. We estimate that Pb exposure accounts for 7 25% of the disease burden among Nigerian children, 
costing the health and education sectors $0.38 – 1.15 billion year

-1
 for every 1 mg/dL increase in BLL. In 

comparison, we estimate that a Pb abatement program in Nigeria will cost $0.076 – 0.23 billion year
-1

. If a Pb 
phase-out program is instituted now to lower the national BLL to 1 mg/dL by 2020, a savings of $2.7-8.0 billion 
would be realized. 
 
Key words: Lead (Pb) poisoning, Cost-benefit analysis, Diseases, Petrochemicals Africa. 

 
INTRODUCTION 

 
Exposure to Pb is widely recognized as a major risk 
factor for several human diseases, and the structure of 
industrial ecological systems have made exposure to Pb 
unavoidable for most people alive today (Needleman, 
1999; Pruss-Ustun et al., 2004; WHO, 2000). In affluent 
countries, sizable investments in the implementation of 
environmental policies prohibiting the addition of Pb to 
many consumer products have resulted in rapid decline 
of human exposures, demonstrable by observed reduc-
tions in the human blood content of Pb (USEPA, 1985; 
Grosse et al., 2002). Unfortunately, the public health 
gains from extensive research on the adverse effects of 
Pb and the remarkable successes of effective policies in 
these industrialized countries have not yet enveloped 
developing countries, and the course of gasoline-fueled 
industrialization remains hazardous to public health 
(OECD, 1999).  
 
 

 
*Corresponding author. E-mail: Oladele.Ogunseitan@uci.edu.  
Phone: 949-824-6350 Fax: 949-824-2056. 

 
 
 

 
Children throughout Africa are particularly vulnerable to 

Pb exposure because of unabated use of leaded gasoline 
and lead- acid batteries in automobiles (Nriagu et al., 
1996 and 1997; Omokhodion, 1994), and recently, unre-
gulated cottage industries associated electronic waste 
recycling (Lincoln et al., 2007). Particular socio- 
ecological and climatic factors also contribute to high 
levels of inhalation and ingestion of Pb-laden aerosol and 
dust (Laidlaw et al., 2005; Ogunfowokan et al., 2004; 
Ogun-sola et al., 1994; Rankin et al., 2005) . Despite the 
initiation of phase-out programs in a few countries, the 
gasoline sold in most African countries contains 0.5 - 0.8 
g/l lead, the highest levels in the world (Thomas, 1995). 

In Nigeria, gasoline with average Pb content of 0.66 g L
-1

 
remains in use (Fakayode and Olu-Owolabi, 2003) . In 
Nigeria’s largest city of Lagos, specific emissions of lead 

exceed 164 kg km
-2

 representing approximately 20% of 
the 2.46 Gg of lead emissions nationwide (Obioh et al., 
1988), and ambient air concentration of Pb ranges up to 

9.58 g m
3
, exceeding WHO recommended annual ave-

rage of 0.5 g m
3
 at all locations (Obioh et al., 2005). 

Furthermore, mean blood lead levels (BPb) measured at 



 
 
 

 

various times and urban locations in Nigeria have ranged 

from 11.4 – 25 g dL
-1

; far exceeding the 10 g dL
-1

 act-

ion dose recommended for the U.S. population (Adeba-
mowo et al., 2006; Ademuyiwa et al., 2005; Nriagu et al., 
1997).  

In addition to automotive and industrial sources, eleva-
ted blood lead levels in children have been attributed to 
paint, household dust, overcrowding and low parental 
income (Charney, 1982; Kapu et al., 1989; Kristensen et 
al., 1993; Landrigan et al., 1976; Nriagu and Pacnya, 
1988). Previous studies in Africa have also shown that 
one of the strongest indicators of childhood BPb was the 
family either owning a car or living in a house located on 
a tarred road (Nriagu et al., 1996). These factors are 
typically only encountered in urban centers. However, the 
geochemical behavior of Pb and its association with sus-
pended particulates suggests that children in remote 
suburban or rural regions may also suffer from Pb expo-
sure, in which case, the adverse affects of Pb should be 
widespread. This hypothesis has not been rigorously tes-
ted within the African continent. Also, it has been rela-
tively simple to quantify the financial costs associated 
with Pb-phase out programs, but the economic costs of 
health effects attributable to lead exposure are typically 
externalized. This has made it difficult for policymakers to 
comprehend cost-benefit scenarios used to justify lead 
abatement programs.  

The goal of this research is to provide cost-benefit 
information to environmental policy makers in Nigeria by 
employing a quantitative comparison of the health cost of 
lead-related disease burden to the cost of a national lead 
abatement program. There are three research objectives:  
(1) the determination of the representative blood-lead 
content of Nigerian children (ages 1 - 6 yrs.) and subse-
quent contribution of environmental lead exposure to the 
burden of disease in Nigeria; (2) the estimation of the 
health costs of environmental lead exposure in Nigeria;  
(3) and the estimation of the cost of a national lead-

abatement program. 

 

METHODS 
 
Assessment of lead exposure 
 
Children (ages 1 – 6 years; N = 306) were recruited for this study 
through the scheduled immunization clinic in the semi-rural region 
of Otukpo, Nigeria (total population of approximately 136,800 
people, of which 45% are younger than 14 years for the study 
period (Population Reference Bureau, 2006). Blood lead concen-
trations were determined by means of an automatic blood lead 

analyzer with a sensitivity range of 1.4 - 65 µg dL
-1

 based on blood 
sample volume of 50 µl (LeadCare, ESA Inc., Chelmsford, MA and 
AndCare Inc., Durham, NC. The equipment was kindly provided by 
the U.S. Centers for Disease Control and Prevention, Atlanta, 
Georgia). The necessary size of the population sample was esti-
mated within the desired margin of error for predicting the popu-
lation mean according to Moore and McCabe (2005): 

 
 
 

 

n  Z  s 
2
   2.96  3.8 

2
  300 

m.65  
 
where: 
Z = z-score (2.96, 99% CI) ; s = standard deviation (3.8 µg dL

-1
; 

Nriagu et al., 1996); m = desired margin of error (± 0.65 µg dL
-1

) 
Informed consent was obtained for all human subjects according 

to standard research ethics, and as approved by the Institutional 
Review Board. Exclusion categories included those previously 
treated for Pb poisoning, those who had not been living in the same 
residence for at least the past 6 months, those who are being 
treated for severe illness, and those not accompanied by a legal 
guardian. In addition to the determination of BPb concentrations, a 
questionnaire was completed by each child subject with the legal 
guardian to record demographic and socioeconomic statistics and 
to assess predictors of Pb exposure and the predominant pathways 
for such exposures. The questionnaire survey was modified from 
the standard instrument used by U.S. Center for Disease Control 
and Prevention to better capture the social, economic, and cultural 
environment of Nigeria. With written consent, the nurse/phleboto-
mist administered the survey and offered the subject a fact sheet 
containing health information on lead exposure in children. 
 
 
Association of lead exposure and disease burden 
 
Lead exposure is implicated in several disease burden categories 
including systemic effects such as hypertension, gastrointestinal 
effects, anemia, nephropathy, and nervous system effects such as 
Intelligence Quotient (IQ) defects and encephalopathy (ATSDR, 
1999; Schwartz, 1991, 1993, 1994; Schwartz et al., 1986). We 
estimated the contribution of Pb exposure to the following disease 
categories in Nigeria: genito-urinary disease, prematurity, dental 
caries, nervous system cancers, congenital anomalies, hyperten-
sion, cerebrovascular disease, low birth weight, and mild mental 
retardation (MMR; IQ levels 50-69) . Nine of the 106 disease cate-
gories included in the World Health Organization’s Global Burden of 
Disease study were included in this study (Murray and Lopez, 1996; 
but see Cooper et al., 1998). A population-adjusted, disease burden 
for Nigeria was estimated from the regional burdens for relative risk 

analysis. The numerical model DISMOD
®

 was used to estimate 

disease burden for two disease categories that were not included in 
the GBD, prematurity and mild mental retardation (http://www.hs-
ph.harvard.edu/organizations/bdu/DisMod.html).  

Our estimate of Pb-associated MMR presented a special cha-
llenge. Pruss-Ustun et al. (2004) estimated the prevalence of men-
tal retardation and cognitive impairment from known, non-congeni-
tal causes (those mentioned above), compared values of developed 
and developing countries, and estimated a rate accounting for the 
increase of risk of mental retardation in developing countries, as 
follows: 

AR  

P
R 


 

P
baseline 


 

P
MR standard 

 
P

MR standard 
 
Where: MR = mental retardation; PR = region-specific prevalence of 
MR from known causes; Pbaseline = prevalence of MR from known, 
non-congenital causes in developed countries; PMR standard = 
prevalence of MR according to the standard distribution of IQ score; 
AR = adjustment ratio  

That lead exposure contributes to IQ deficit is universally accep-

ted, but there is no consensus on the dose response relationship 

(Lanphear et al., 2000; Moore et al., 1977; Pocock et al., 1994; 



 
 
 

 
Table 1. Variables for the cost of lead abatement in Nigeria. 

 

  Cost  
 

  ($/liter) Consumption 
 

 Unleaded 0.01 *6,837 
 

 Gasoline   
 

 Non-Pb 0.01 6,837 
 

Abatement Additive   
 

Refinery 0.006 1,408 
 

Factors 
 

 Retooling   
 

 Tetraethyl 0.002 6,837 
 

 Lead (TEL)   
 

 Domestic 0.16 1,408 
 

 Gasoline   
 

Gasoline Foreign 0.16 5,429 
 

Source Gasoline   
 

 Total 0.16 6,837 
 

 Gasoline   
 

 
*(U.S. DoE, 2000) 

 

 
Lynn and Vanhanen, 2002; Stouthard et al., 1997). Based on the 
meta-analysis conducted by Popcock et al. (1994) and by Schwartz 
(1994), we relied on the following categories defined by three levels 
of exposure to Pb measured by blood Pb content. Children with 

relatively low BLLs (5 - 8 g/dL) suffer a 1.0 IQ deficit; those with 

medium BLL (9 - 15 g/dL) suffer 2.0 IQ deficits, and children in the 

high Pb exposure category (> 16 g/dL) suffer 3.0 IQ deficit.  
Pruss-Ustun et al. (2004) estimated lead-induced MMR to be 

0.385/1000 for Sub-Saharan Africa (SSA) populations, compared to 
0.256 per 100 people in Europe. We judged this estimate to be 
inadequate for Nigeria based on the assumption of global average 
IQ score of 100. Instead, we relied on the baseline IQ estimates of 
Lynn and Vanhanen (2002) that are more localized in perspective, 
providing average IQ scores for SSA and Nigeria as 70 and 67, 
respectively. The present study also departs from the Pruss-Ustun 
et al. (2004) assessment in the following way. Instead of extracting 
the fraction of lead-induced MMR from an overall MMR rate in 
Nigeria, an estimation of the IQ drop due exclusively to lead 
exposure was assessed on the basis of the range of measured 
BLLs and the IQ decrements attributed to those ranges in the 
clinical literature. To estimate the burden attributable to MMR, we 
adopted the approach used in a Dutch Burden of Disease Study 
where a severity weight of 0.06 was assigned for deficits in IQ 
between 1 - 4 points (Stouthard et al., 1997).  

The proportion of disease cases attributable to Pb exposure to an 

environmental risk factor (Attributable Faction) was based on 

Miettenen’s approach (1974): 

AFj   
P(RR

j  1) 
 

P(RR j  1)  1 

where: AF j  the fraction of burden from some cause j (lead 

exposure); RR j  the relative risk of disease for cause j in the 

exposed to unexposed group; P = Prevalence of exposure.  
The attributable fraction was used to derive an estimate of the 

Lead Attributable Burden (LABD) for low, medium, and high Pb ex-

posures given Relative Risks (or Odds Ratios) for each cause of 
death and disability related to the exposure, levels of exposure (pre 

  
  

 
 

 
Table 2. Summary of blood lead levels in children, ages 1-6, 

Otukpo. 
 

  Mean   %>10 

Sex n [BPb] Range SD ug/dL 

Female 138 8.9 (2.1,23.8) 4.2 32.5 

Male 168 9.8 (2.2,31.8) 4.8 35.0 

Total 306 9.4 (2.1,31.8) 4.2 34.3 
 

 
valence), and burden of disease due to each cause of death and 

disability in a given population: 
 

AB  AFj B j 

 
where: AB = Attributable Burden for a risk factor; AFj = Fraction of 
Burden from cause j 
Bj = population level burden of cause j 

 
Economic cost of lead exposure 
 
The U.S. EPA estimated the cost of a lead abatement program to 
be approximately 500 million dollars per year in 1985 (USEPA 
1985). Estimates for the cost of a lead additive (Tetraethyl lead 
(TEL), $0.002/liter), refinery overhaul ($0.006/liter), and non-lead 
additive (Methy tert butyl ether (MTBE), $0.01/liter) were derived 
from Thomas and Kwong (2000). The average cost of gasoline in 
Nigeria was estimated to be approximately $.16/liter (Obioh et al., 
2005). The annual consumption of domestic and imported gasoline 
in Nigeria is 24,260 and 93,550 barrels per day, respectively (US 
DoE, 2000). Thus, the total consumption of leaded gasoline in Nige-
ria is 117,810 barrels per day (Table 1). Schwartz (1993) estimated 

that $17.2 billion dollars per year would be saved by a 1  g/dL red-
uction in blood levels per year across the U.S. population. We used 
a similar approach to estimate the economic cost of lead exposure 
in Nigeria, but with modifications that capture issues specific to 
Nigeria and time differentials, including adjustments according to 
the consumer price index (CPI), and gross national income in pur-
chasing power parity (GNI-PPP) of 2.3% for the study period 
(Population Reference Bureau, 2006). 
 

 

RESULTS AND DISCUSSION 
 
Blood lead levels 

 

Blood lead levels measured in children of Otukpo are 
summarized in Table 2. The mean for all children was 9.4 

g/dL (SD = 4.2, n = 306). The mean value for males 
(55% of the sample; Table 3) was not significantly higher 
than for females. The highest BLL measured was 31.8  
g/dL, which is below the U.S. standard of 45 g/dL for 
lead poisoning treatment with chelation therapy. The 
proportion of children having BLL above the USEPA 

action level of 10 g/dL is more than one third. 
Figure 1 shows a comparison of BLL distribution among 

children residing in Otukpo with previous reports of blood 
lead levels for children in the more urbanized city of 

Kaduna and other distantly located cities (Nriagu et al., 



 
 
 

 
 30         

 

P
o

p
u

la
ti

o
n
 25         

 

20       
Otukpo  

       
 

15       Kaduna 
 

10         
 

%
 

        
 

         
 

 5         
 

 0         
 

 5 7 9 11 13 15 17 19 21 
   

Blood Lead Concentration (ug/dL) 

 
Figure 1. Blood lead levels measured in Nigerian children. 

 

 
Table 3. Summary of demographic characteristics in 

children, ages 1 - 6, Otukpo.  
 

Characteristics Percentage  
Gender  

Male  54.9 

Female  45.1 

Age of Child    

1 Year  19.9 

2 Years  18.3 

3 Years  15.0 

4 Years  13.7 

5 Years  15.4 

6 Years  17.6 

Born in Otukpo    

Child  87.9 

Mother  42.8 

Father  34.6 

Average Household Size 6.8 People 

Maternal Literacy  64.7 

Education Level Mother  Father 

0-4 Years 61.5  55.6 

5-8 Years 17.9  21.6 

9-12 Years 18.2  15.0 

>12 Years 2.3  7.8 

Occupation Mother  Father 

Self-Employed 54.6  30.9 

Professional 10.1  15.4 

Factory Worker 1.0  4.9 

Homemaker 14.1  0.0 

Farmer 13.4  27.8 

Other 13.1  18.6  
Years Child has Lived in Current Residence  

 1 Year 28.1 

 2 Years 20.9 

 3 Years 15.0 

 4 Years 12.4 

 5 Years 10.1  

 
 
 

 
Table 3. Contd.  

 

6 Years  12.1 

Type of Housing  

Detached  21.2 

Attached  62.4 

Apartment  15.4 

Other  1.0 

Housing Construction Material  

Brick/Block  98.0 

Wood  0.7 

Other  0.7 

Unknown  0.7 

Source of Drinking Water  

Pipes  29.7 

Public Faucet  1.6 

Well  61.8 

Barrels  2.3 

Bottled  1.6 

Combination  3.0  
Time Spent Away From Home by Child  

0 Hours 84.3 

1 Hour 0.3 

2 Hours 0.7 

3 Hours 2.9 

4 Hours 2.6 

>4 Hours 9.4 

Children That Wash Hands 40.8 

Mothers  that  Cook/Store 36.0 
Food/Water in Clay Pots  

 

 

1997; Adeniyi and Anetor, 1999) . The population of 
Kaduna is approximately 1.5 million people in 2002. The 
mean BLL in Kaduna children ages 1 - 6 years old is 10.6 

µg dL
-1

 (± 3.8); with total atmospheric emissions of Pb in 
the region being 150 tons annually, and 97% of that 
exposure coming from leaded gasoline (Nriagu et al., 
1996; Obioh et al., 1988).  

Table 3 shows a summary of the Socio-Demographic 
data that was collected through the epidemiological 
survey. Almost 90% of the children were born in Otukpo, 
but less than half of the parents were indigenous. The 
average household size was approximately 7 individuals 
and most lived in attached compound houses constructed 
of cement bricks with groundwater wells being the source 
of drinking water. Mean BLL was significantly associated 
with household size, maternal literacy, parental occupa-
tion, home floor type, time spent outside the home, 
residential proximity to a ceramics shop, and by parental 
employment in a print shop (p<.05), but not with age, 
parental education, housing construction type or detach-
ment status, drinking water, and frequency of hand-to- 



  
 
 

 
Table 4. Deaths (x1000) and DALYs (x1000) from all Pb-linked diseases for males and 

females, ages 0-14. 
 

 Deaths, 0-14 DALYs, 0-14 

Pb-Disease Category male female male female 

Genito-Urinary Disease 16 13 710 541 

Prematurity* 384 384 2,295 2,295 

Dental Caries 0 0 129 127 

Nervous System Cancers 7 6 270 210 

Congenital Anomalies 32 33 2,455 2,628 

Hypertension** 2 2 66 69 

Cerebrovascular Disease 9 9 313 298 

Pb-Mild Mental Retardation (MMR) 0 0 2,463 2,414 

Low Birth Weight*** 262 234 9,827 8,873 

Sub-Saharan Africa (SSA) 712 681 18,528 17,455 

SSA,M&F  1,393 35,983 

Nigeria 121 116 3,150 2,967 

Nigeria, M & F  237 6,117 
 

*DALYs calculated using DISMOD with incidence rates from (Antilla et al., 1995).  
**DALY data from Type I Diabetes, ***Low Birth Weight is the largest category within Perinatal 

Conditions 
 

 
Table 5. Pb-linked burden of disease percentages (BDPb%). 

 

  Deaths  DALYs 

 male female male female 

PbBD% of SSA 2.42 2.75 1.82 2.04 

PbBD% of SSA, 0-14 4.57 5.31 2.97 3.34 

PbBD% of SSA, 0-14, m/f  4.90  3.14 

PbBD% of Nigeria 14.25 16.18 10.71 11.99 

PbBD% of Nigeria, 0-14 26.86 31.25 17.48 19.67 

PbBD% of Nigeria, 0-14, m/f  29.06  18.58 
 

 

mouth behavior (Ogunseitan and Smith, submitted). 

 

Lead-associated burden of disease estimates 

 

Table 4 shows the results for overall Deaths and DALYs 
by gender for children, ages 0-14, of Sub-Saharan Africa 
(SSA) and Nigeria. Table 5 shows the results by gender 
for lead-linked disease burden for children in Nigeria. The 
data are shown as a percentage of SSA burden, SSA 
childhood burden, Nigerian burden, and Nigerian child-
hood burden. Table 6 shows the medium estimate for 
DALYs of all nine disease burden categories by gender 
for children, ages 0-14, for both SSA and Nigeria. Also, 
the ORs that were found in the literature are shown. The 
three exposure categories are classified as low exposure 

(5-8 g/dL), medium exposure (9- 15 g/dL), and high ex-

posure (>16 g/dL). There is no OR for lead-attributed 

mild mental retardation (MMRPb) required, because by 

definition, 100% of MMRPb is due to lead exposure. Table 

 
 

7 shows the medium estimate of both the attributable risk 
and attributable burden for lead exposure across all three 
exposure categories for children, ages 0 - 14, in SSA and 

Nigeria. Also, the Pb-attributed burden of disease (BDPb) 

is shown as a percentage of the total Nigerian BD, and 
the total Nigerian childhood BD. Nigerian childhood BLLs 

of 5 - 8 g/dL account for approximately 2.18% of the tot-

al Nigerian childhood burden, BLLs of 9 - 15 g/dL acco-

unt for 7.50%, and BLLs >16 g/dL account for 5.07%. 
Combined all lead exposure accounts for approximately 
14.74% of the total Nigerian childhood disease burden. 

 

Health costs of lead (Pb) exposure 
 
The estimates of childhood health costs of lead exposure 
are outlined in Table 8. The total costs are presented in 
millions of dollars. While all of the sub-categories (medi-
cal, compensatory education, lost earnings, IMR, and 
neonatal care) show significant health costs of Pb expos- 



 
 
 

 
Table 6. Dalys and odds ratios for 9 Pb-linked diseases (Medium estimate). 

 

Pb-Disease Category  DALYs, 0-14  OR @ 3 PbB Levels* 

  male female total 5-8 9-15 >16 

Genito-Urinary Disease 710 541 1251 1.0 1.9 3.8
1
 

Prematurity 2295 2295 4590 2.2 4.3 8.6
2,3

 

Dental Caries 129 127 256 6.8 9.6
4
 13.5

4
 

Nervous System Cancers 270 210 480 2 5.5
5
 11.0

5
 

Congenital Anomalies 2455 2628 5083 1.0 1.6 3.2
6
 

Hypertension 66 69 135 1.0 1.5
7
 3 

Cerebrovascular Disease 313 298 611 2.2
8
 4.5

8
 6.8

8
 

Pb-Mild Mental Retardation 2463 2414 4877 N/A N/A N/A 

Low Birth Weight 9827 8873 18700 1.2 2.4 4.7
9
 

Total SSA 18528 17455 35983    

Total Nigeria 3150 2967 6117    
 

*BLLs are presented in ug/dL. Not all the Odds ratios were available for all three blood lead levels in every disease 

category. Estimates were used in those cases. 
1
(Antilla et al., 1995) 

2
(Asien et al., 2000); 

3
(Khera et al., 1980); 

4
(Gemmel et al., 2002); 

5
(Landrigan et al., 1976) 

6
(Kristensen et al., 1993) 

7
(Factor-Litvak et al., 1996) 

8
(Gomaa et 

al., 2002) 
9
(Kristensen et al., 1993). 

 

 

Table 7. Attributable risks and attributable Burden for 9 Pb-linked diseases 

(Medium estimate) 
 

 AR for PbB Levels *AB for PbB Levels 

Pb-Disease Category 5-8 9-15 >16 5-8 9-15 >16 

Genito-Urinary Disease 0.0 33.5 21.9 0 419 274 

Prematurity 29.0 64.9 43.2 1,330 2,978 1,982 

Dental Caries 6.8 9.6 13.5 17 25 35 

Nervous System Cancers 25.4 71.6 50.0 122 344 240 

Congenital Anomalies 0.0 25.1 18.0 0 1,278 917 

Hypertension 0.0 21.9 16.7 0 30 23 

Cerebrovascular Disease 29.0 66.2 36.7 177 405 224 

Pb-Mild Mental Retardation 100.0 100.0 100.0 1,609 1,609 1,609 

Low Birth Weight 6.4 43.9 27.0 1,191 8,218 5,050 

Total SSA    4,446 15,306 10,353 

Total Nigeria    756 2,602 1,760 

% Nigeria BOD Attributable to Pb   1.40 4.80 3.25 

% Nigeria BOD, Attributable to Pb (0-14)  2.18 7.50 5.07   
*Attributable Burden is presented in DALYs (x1000) 

 

 

ure, lost earnings and increased IMR appear to have the 
largest impact on overall cost. The total childhood health 
cost was estimated to be $10.3 billion ($238 million GNI-  
PPP adjusted), or 29.8 billion naira annually for a 1 g/dL 
increase in BLL. Considering that the average BLL in 

Nigerian children is approximately 10 g/dL, the cost of 
lead exposure could be ten times higher than what is 
reported here. Thus, if Nigeria is able to decrease 

national BLL average by 5 g/dL, the country could gain 
more than $1 billion in savings annually from childhood 
health costs. 

 
 

 

Table 9 shows the results for the adult health costs of 
lead exposure. The total health costs are presented in 
millions of dollars. Mortality costs of hypertension–related 
deaths provide the driving force behind the bulk of the 
adult health costs, accounting for $6.6 billion out of $7 
billion (94%) estimated for total adult health costs. Table 
10 shows the estimates for the total health cost annually 
for the entire population. It also provides the annual per 
capita health cost of lead exposure, the annual health 
cost as a percentage of GNI-PPP, and the annual health 
cost as a percentage of the average per capita health ex- 



  
 
 

 
Table 8. Childhood health costs of lead exposure. 

 

Children Variable $(M) GNI-PPP Adjusted Million Naira 
 

 Average blood lead concentration 9.8 ug/dL   
 

 Number of children requiring 160,909   
 

Medical Costs chelation therapy    
 

 Cost of chelation therapy 1,920   
 

 Total Medical Costs 309 7 888 
 

 Number of children who receive 162,231   
 

Compensatory education    
 

Education Cost of education 4,902   
 

 Total Compensatory Education 795 18 2,286 
 

 Cost    
 

 Number children, age 6 3,515,600   
 

Earnings Increase in earnings of a 1 ug/dL 1,920   
 

 reduction in BLL    
 

 Total Earnings Lost 6,750 155 19,406 
 

 IMR 75/1000   
 

 1 ug/dL reduced maternal blood – 74.9/1000   
 

 IMR    
 

Infant Mortality Value of statistical life 4,429,840   
 

 Number of live births in Nigeria, 5,192,000   
 

 2002    
 

 Number of reduced deaths 519   
 

 Total IMR Cost 2,299.09 52.88 6,609.88 
 

 # of NICU admissions 1,752,300   
 

 Reduced NICU admissions 1,749,960   
 

Neonatal Care 
Number of fewer NICU admissions 2,340 

  
 

   
 

 Cost of NICU 86,661   
 

 Total Neonatal Cost 202.79 4.66 583.01 
 

 Total Childhood Cost 10,356.03 238.19 29,773.58 
 

 

 

expenditure. All of these health cost figures are for a 1  
g/dL change in BLL. The total health cost is presented 
as a low, medium, and high value. The low value was 
calculated by subtracting the cost of compensatory edu-
cation and NICU from the total. It is hypothesized that 
Nigeria could have significantly less compensatory edu-
cation than the United States for children who are aca-
demically challenged. Likewise, the frequency of children 
admitted into NICU in Nigeria could be much lower than 
the US. Based upon these assumptions, the low estimate 
for the health costs due to lead exposure is estimated to 
be approximately $377 million. The high value for health 
costs due to lead exposure was taken from Landrigan et 
al. (2002) who estimated that the health costs due to lead 
exposure for the cohort of children born in 2000 is app-
roximately $43.4 billion (USD, 1997). This estimate was 
adjusted using both the Consumer Price Index (CPI) and 
the GNI-PPP ratio between the US and Nigeria (2.3%). 
The resultant health cost estimate after allowing for these 
adjustments is approximately $1.15 billion. 

 

 

Cost of lead abatement 
 

Table 11 illustrates the cost of a lead abatement prog-
ram in Nigeria. The cost is a combination of four sub-
categories: the cost the refinery upgrades, the cost of a 
non- lead additive, the cost of unleaded gasoline, and the 
cost of TEL. These sub-category costs are presented in 
$/Liter. To calculate the overall cost of the abatement 
program, the cost of TEL is subtracted from the summed 
costs of refinery upgrades, non-lead additive, and un-
leaded gasoline. Using the national gasoline consump-
tion provided by the Department of Energy (DOE), the 
medium overall estimated cost of a lead abatement pro-
gram for Nigeria is approximately $194 million for the first 
year. This is approximately 48.5% of the health cost of a 

1 g/dL increase in BLL per year g/dL. 
The low estimate, using the low estimate cost of $0.01 

/L reported by the Organization for Economic Develop-

ment (OCED) for lead phase out is $76 million per year 
(11). The high estimate, using the high estimate cost of 



     

  Table 9. Adult health costs of lead exposure.    
       

  Adults Variable $(M) GNI-PPP Adjusted Million Naira 

  Medical costs     

   Number of cases of hypertension 288,712   
  Hypertension Annual medical costs 812   

   Total Medical Cost 234.43 5.39 674.00 

   Number of cases of heart attacks 1,454   
  Heart attacks Medical costs 33,960   

   Total Medical Cost 49.38 1.14 141.96 

   Number of cases of stroke 591   
  Strokes Annual medical costs 26,574   

   Total Medical Cost 15.71 0.36 45.15 

  Lost wages     

   Number of cases of hypertension 288,712   
  Hypertension Annual lost earnings 115.0   

   Total Earnings Lost 33.20 0.76 95.46 

   Number of cases of heart attacks 1,454   
  Heart Attacks Annual lost earnings 31,000   

   Total Earnings Lost 45.07 1.04 129.59 

   Number of cases of stroke 591   
  Strokes Annual lost earnings 17,716   

   Total Earnings Lost 10.47 0.24 30.10 

   Number of deaths 1,500   
  Mortality Value of statistical life 4,429,840   

   Total Mortality Cost 6,644.76 152.83 19,103.69 

  Total Adult Cost  7,033.02 161.76 20,219.94 
 
 

 
Table 10. Total health costs of lead exposure. 

 

 $M GNI-PPP 
†
Million 

Low Estimate (2003) Adj. $M Naira 

Total annual health cost to Nigeria of 1 g/dL BPb *16,391 377 47,124 

Annual per capita cost 126 2.90 362 

Annual cost as percentage of GNI-PPP 0.36% 0.36% 0.38% 

Annual cost as percentage of per capita health expenditures 14% 14% 14% 

Medium Estimate    

Total annual health cost to Nigeria of 1 g/dL BPb 17,389 400 49,993 

Annual per capita cost 134 3.08 385 

Annual cost as percentage of GNI-PPP 0.38% 0.38% 0.38% 

Annual cost as percentage of per capita health expenditures 15% 15% 15% 

High Estimate    

Total annual health cost to Nigeria of 1 g/dL BPb **49,810 1,145 143,203 

Annual per capita cost 383 8.81 1,102 

Annual cost as percentage of GNI-PPP 1.10% 1.10% 0.38% 

Annual cost as percentage of per capita health expenditures 44% 44% 44%   
*Low estimate = Total health costs – cost of compensatory education and NICU. **High estimate = ($43.4 billion) (CPI, 

2003), (49). 
†
Million Naira. 



  
 
 

 
Table 11. Cost of lead abatement in Nigeria. 

 

  Cost ($/liter) 
‡
Cons. (10

6
 Cost  (M$/yr Cost  (M$/yr Cost 

   l/year) 1995) 2003) (
†
MN/yr, 2003) 

 Unleaded Gasoline 0.01 6,837 68 82 10,250 

Abatement factors Non-Pb  Additive 0.01 6,837 68 82 10,250 

 Refinery Retooling 0.006 6,495 39 47 5,875 

 Tetraethyl  Lead (TEL) 0.002 6,837 14 17 2,125 

 Domestic Gasoline 0.16 6,495 1,039 271 33,821 

Gasoline source Foreign Gasoline 0.16 342 55 66 8,250 

 Total  Gasoline 0.16 6,837 1,094 1,313 164,148 

Low estimate       

 Total annual cost of abatement   *75.6 24,250 

 Pb abatement cost / Pb health cost   0.189 0.189 
 Abatement as % of health cost   18.9% 18.9% 

Medium estimate       

 Total annual cost of abatement   194 24,250 

 Pb abatement cost / Pb health cost   0.485 0.485 

 Abatement as % of health cost   48.5% 48.5% 

High estimate       

 Total annual cost of abatement   *227 24,250 

 Pb abatement cost / Pb health cost   0.567 0.567 
 Abatement as % of health cost   56.7% 56.7%   
*Low estimate = ($.01/L) (Liters consumed/year) (11). **High Estimate = ($.03/L) (Liters consumed/year) (11). 

‡
Consumption, 

†
Million 

Naira. 
 

 

$0.03/L reported by OECD, is $227 million per year 
(OECD, 1999).  

In conclusion, we have shown that lead exposure 
remains a major health risk factor in all Nigeria commu-
nities, both rural and urban. The most important – and 
controllable – source of exposure is leaded automobile 
fuels. Arguments based on the enormous costs to society 
of switching to unleaded fuels are weak in the face of 
counterarguments based on the even more astounding 
health care and special educational costs associated with 
lead exposure. In the presence of alternative renewable 
fuels such as ethanol (Thomas and Kwong, 2000), the 
removal of lead from all fuels in Nigeria – and all coun-
tries in sub-Saharan Africa – should not be delayed a sin-
gle day further. 

 

ACKNOWLEDGMENTS 
 
This study was supported in part by funding and resour-
ces provided by the Global Forum for Health Research, 
Switzerland; by the U.S. Centers for Disease Control and 
Prevention; and by the U.S. National Science Foundation 
(CMS-0524903). Additional support was provided by the 
Program in Industrial Ecology at UC-Irvine. We are grate-
ful for the kind support provided by Dr. Sunday Ochenjele 
at Mount Zion hospital, Otukpo; and by Shime-nenge 
Imadu, Secretary of the Ethical Committee of the Ministry 
of Health and Human Services, Benue State, Nigeria. 

 
 

 
REFERENCES 
 
Adebamowo EO, Agbede OA, Sridhar MKC, Adebamowo CA (2006). 

An examination of knowledge, attitudes and practices related to lead 
exposure in South Western Nigeria. BMC Public Health 6 (82): 1–7. 

Ademuyiwa O, Ugbaja RN, Idumebor F, Adebawo O (2005). Plasma 
lipid profiles and risk of cardiovascular disease in occupational lead 
exposure in Abeokuta, Nigeria. BMC Lipids in Health and Disease, 
4(19): 1–7.  

Adeniyi FAA, Anetor JI (1999). Lead poisoning in two distant states of 
Nigeria: an indication of the real size of the problem. Afr. J. Med and 
Med. Sci. 28: 107-112. 

Agency for Toxic Substances and Disease Registry (1999). 
Toxicological profile for lead (update). US Department of Health and 
Human Services, Atlanta, Georgia. 

Anttila A, Heikkila P, Pukkala E, Nykyri E, Kauppinen T, Hernberg S, 
Hemminki K (1995). Excess lung cancer among workers exposed to 
lead. Scan J Wrk Environ. Health, 21(6): 460-469. 

Asien AO, Olarewaju RS, Imade GE (2000). Twins in Jos, Nigeria: a  
seven year retrospective study. Med. Sci. Monit. 6(5): 945-950.  

Charney, E. (1982). Lead poisoning in children: The case against 
household lead dust. In: Chisolm J.J. and O'Hara D.M. (eds.), Lead 
Absorption in Children. Urban & Schwarzenberg, Baltimore-Munich, 
pp. 35-42.  

Cooper R.S., Osotimehin B., Kaufman J.S., Forrester T. (1998). 
Disease burden in SSA: what should we conclude in the absence of 
data? Lancet 351: 208-210. 

Factor-Litvak P., Kline J., Slavkovich V., Graziano J. (1996). Blood lead 
and blood pressure in young children. Epidemiol. 7: 633-637. 

Fakayode, S.O, Olu-Owolabi, B.I. (2003) Heavy metal contami-nation of 
roadside topsoil in Osogbo, Nigeria: its relationship to traffic density 
and proximity to highways. Environ. Geol. 44: 150-157. 

Gemmel A, Tavares M, Alperin S, Soncini J, Daniel D, Dunn J, Crawford 

S, Braveman N, Clarkson TW, McKinlay S, Bellinger DC. (2002). 

Blood lead level and dental caries in school-age children. 



 
 
 

 
Environ. Health Perspect, 110: 625-630.  

Gomaa A, Hu H, Bellinger D, Schwartz J, Schnaas L, Gonzalez-Cossio 
T, Peterson K, Aro A, Hernandez-Avila M (2002). Maternal bone lead 
as an independent risk factor for fetal neurotoxicity: a prospective 
study. Ped, 110(1): 110-118.  

Grosse SD, Thomas DM, Schwartz J, Jackson RJ (2002). Economic 
gains resulting from the reduction in children’s exposure to lead in the 
Unites States. Environ. Health Perspect. 110: 563-569. 

Kapu M.M., Basak B., Job A., Umara I.O., Kalla S.M., Mohammad B.Y., 
Harun B.A., Schaeffer D.J. (1989). Studies in human exposure to 
environmental lead in Zaria, Nigeria. Trace Elements Med. 6: 178-
181.  

Khera AK, Wibberley DG, Dathan JG (1980). Placental and stillbirth 
tissue lead concentrations in occupationally exposed women. Br. J. 
Ind. Med. 37: 394-396. 

Kristensen P, Irgens LM, Dalveit AK, Anderson A (1993). Perinatal 
outcome among children of men exposed to lead and organic 
solvents in the printing industry. Am. J. Epidemiol. 137(2): 134-144. 

Laidlaw MAS, Mielke HW, Filippelli GM, Johnson DL, Gonzales CR 
(2005). Seasonality and children’s blood lead levels: Developing a 
predictive model using climatic variables and blood lead data from 
Indianapolis, Indian, Syracuse, New York, and New Orleans, 
Louisiana (USA). Environ. Health Perspect. 113: 793–800.  

Landrigan PJ, Baker EL, Jr, Feldman RG, Cox DH, Eden KV (1976). 
Increased lead absorption with anemia and slowed nerve conduction 
in children near a lead smelter. J. Pediatr. 89: 904-910. 

Landrigan PJ, Schechter CB, Lipton JM, Fahs MC, Schwartz J (2002). 
Environmental pollutants and disease in American children: estimates 
of morbidity, mortality, and costs for Lead poisoning, asthma, cancer, 
and developmental disabilities. Environ. Health Perspect, 110: 721-
728.  

Lanphear BP, Dietrich K, Auinger P, Cox C (2000). Cognitive deficits 
associated with blood lead concentrations < 10 µg/dL in United 
States children and adolescents. Pub Hlth Rep, 115: 521-529. 

Lincoln JD, Ogunseitan OA, Saphores J-D, Shapiro A.A (2007). 
Leaching Assessments of Hazardous Materials in Cellular Telepho-
nes. Environ. Sci. Technol., 41: 2572 -2578. 

Lynn R, Vanhanen T (2002). IQ and the Wealth of Nations. Westport, 
CT: Praeger.  

Miettenen OS (1974). Proportion of disease caused or prevented by a 
given exposure, trail or intervention. Am. J. Epidemiol. 99:325-332.  

Moore MR, Meredith PA, Goldberg A (1977). A retrospective analysis of 
blood lead in mentally retarded children. Lancet, 520: 717-719. 

Moore MR., McCabe L.M. (2005). Introduction to Practice of Statistics, 
5th Edition, W. H. Freeman and Co. and Sumanas, Inc. p. 896.  

Murray C., Lopez A, (1996) eds. The Global Burden of Disease: Volume 
1 (World Health Organization, Harvard School of Public Health, and 
The World Bank, Washington, D.C. p. 1022. 

Needleman HL (1980). Lead and neuro psychological deficit. In: 
Needleman HL (ed.) Low Level Lead Exposure: the clinical implica-
tions and current research. New York: Raven Press, pp. 43-51. 

Needleman HL (1983). Low level lead exposure and neuropsychological 
performance. In: Rutter M, Jones RR (eds.), Lead Versus Wealth, 
John Wiley and Sons Ltd., pp. 229-242. 

Needleman HL (1999). History of lead poisoning in the world. In: Lead 
poisoning prevention and treatment: implementing a national program 
in developing countries. George AM (ed.). The George Foundation, 
Bangalore, India.  

Needleman HL, Gunnoe C, Leviton A, Reed R, Peresie H (1979). 
Deficits in psychologic and classroom performance of children with 
elevated dentine lead levels. N Eng. J. Med, 300: 689-732. 

Needleman HL, Landrigan PJ (1981). The health effects of low level 
exposure to lead. Ann Rev. Public Wealth, 2: 277-298.  

Needleman H.L., Schell A., Bellinger D. (1990). The long-term effects of 
low dose exposure to lead in childhood: an 11 year follow-up report. 
N Eng. J. Med. 322: 83-88. 

Nriagu JO, Pacnya JM (1988). Quantitative assessment of worldwide 

contamination of air, water and soils by trace metals. Nature, 333: 

134-139. 

 
 
 

 
Nriagu JO, Blankson ML, Ocran K (1996). Childhood lead poisoning in 

Africa: a growing public health problem. Sci. Total Environ. 181: 93-
100. 

Nriagu J, Oleru NT, Cudjoe C, Chine A (1997). Lead poisoning of 
children in Africa, III. Kaduna, Nigeria. Sci. Tot. Environ. 197: 13-19. 

Obioh IB, Akeredolu FA, Asubiojo OI (1988). National inventory of air 
pollutants in Nigeria. Report of the Environmental Research 
Laboratory, Obafemi Awolowo University. 

Obioh, I.B., Olise, F.S., Owoade, O.K., and Olaniyi, H.B. (2005) 
Chemical characterization of suspended particulates along air 
corridors of motorways in two Nigerian cities. J. Appl. Sci. 5: 347-350. 

Ogunfowokan AO, Asubiojo OI, Adeniyi AA, Oluyemi EA. (2004) Trace 
lead, zinc, and copper levels in Barbula labarenensis as a monitor of 
local atmospheric pollution in Ile-Ife, Nigeria. J. Appl. Sci. 4: 380-383.  

Ogunsola O.J., Oluwole A.F., Asuobiojo O.I., Olaniyi H.B., Akeredolu 
F.A., Akanle O.A., Spyrou N.M., Ward N.I., Ruck W. (1994). Traffic 
pollution: preliminary elemental characterization of roadside dust in 
Lagos, Nigeria. Sci. Total Environ. 147: 175-184.  

Omokhodion F.O. (1994). Blood lead and tap water lead in Ibadan, 
Nigeria. Sci. Total Environ. 151:187-190.  

Organization for Economic Cooperation and Development/United Nat-
ions Environment Program. (1999). Phasing lead out of gasoline: an 
examination of policy approaches in different countries. Paris: OECD. 

Pocock SJ, Smith M, Baghurst PA (1994). Environmental lead and 
children’s intelligence: a systematic review of the epidemiological 
evidence. Br. Med. J. 309: 1189-1197. 

Population Reference Bureau (2006). World Population Data Sheet. 
Internet Communications: http://www.prb.org/. Accessed on 6 Aug-
ust, 2007. 

Pruss-Ustun A, Fewtrell L, Landrigan PJ, Ayuso-Mateos JL (2004). 
Lead Exposure, pages 1495 – 1552 In: Ezzati, M., A.D. Lopez, A. 
Rodgers, and C.J.L. Murray. Comparative Quantification of Health 
Risks: Global and Regional Burden of Disease Attributable to 
Selected Major Risk Factors. World Health Organization, Geneva.  

Rankin CW, Nriagu JO, Aggarwal JK, Arowolo TA, Adebayo K, Flegal 
RA (2005). Lead contamination in cocoa and cocoa products: isotopic 
evidence of global contamination. Environ. Health Perspect. 113: 
1344–1348.  

Schwartz J (1994). Low level lead exposure and children’s IQ: a meta  
analysis and search for a threshold. Environ. Res. 56: 42-55. 

Schwartz  J.  (1993).  Societal  benefits  of  reducing  lead  exposure. 
Environ. Res. 66: 105-124.  

Schwartz J (1991). Lead, blood pressure, and cardiovascular disease in 
men and women. Environ. Health Perspect., 91: 71-75.  

Schwartz J, Anglo C, Pitcher MS (1986). Relationship between 
childhood blood lead levels and stature. Pediatrics, 77: 281-288. 

Stouthard MEA, Essink_Bot ML, Bonsel GJ (1997). Disability weights 
for diseases in the Netherlands. Erasmus University, Department of 
Public Health, Rotterdam. Vos T. 

Thomas VM (1995). The elimination of lead in gasoline. An Rev. Ener 
Environ., 20: 301-324.  

Thomas VM, Kwong A (2000). Ethanol as a lead replacement: phasing 
out leaded gasoline in Africa. Energy Policy, 10: 1-11. 

United States Environmental Protection Agency (1985). Costs and 
benefits of reducing lead in gasoline, final regulatory impact analysis. 
EPA-230-05-85-006, Washington, D.C. 

United States Department of Energy (2000). Country energy data 
report. Internet communications: http://www.eia.doe.gov/em-
eu/world/country/cntry_NI.html. Accessed on 6 August 2007. 

World Health Organization (2000). Environmental lead exposure: a 

public health problem of global dimensions. WHO Bulletin, Tong S, 

Yasmin E,Von S, Prapamontol T, (eds.) Geneva, Switzerland. 


