The consequences of lead exposure have been documented for centuries. Childhood lead
poisoning, in particular, is one of the most carefully studied and documented environmental exposures
worldwide. However, despite awareness that lead exposure can compromise health, and that lead
poisoning is completely preventable, lead continues to contribute significantly to the global burden of
disease.
There are many sources of lead in the environment and these sources differ markedly between
developed and developing countries. In developed countries such as the United States (US), children
most at risk for lead exposure tend to be of a lower socioeconomic status and are most often exposed
through peeling paint or leaded pipe solder. In developing countries, the exposures are frequently
associated with smelting, mining or recycling efforts. Lead is still often added to paints, pigments, toys,
traditional medicines and cosmetics—exposures that do not remain confined to their country of origin.
The greatest exposure concern for the general population, leaded gasoline, has been removed from the
majority of countries worldwide and subsequent blood lead levels have declined steadily as this process
has been accomplished.
In some nations, such as the US, India and Indonesia, to name a few, studies have shown a
precipitous drop in childhood lead levels after leaded gasoline has been outlawed. For instance, at the
time US federal legislation was enacted in the 1970’s to eliminate the use of leaded gasoline, the median
blood lead level (BLL) of US children ages 1-5 was 15 µg/dL (from 1976 to 1980). In 1988-1991, the
median was 3.6 µg/dL, and by 1999, the median BLL had decreased to 1.9 µg/dL (American Academy of
Pediatrics 2005). Leaded gasoline was phased out in Vietnam in 2001. Unfortunately, no surveillance
blood lead levels are available to confirm that Vietnamese children are now at decreased risk of
complications due to lead exposure. Even with the elimination of leaded fuel, elevated pediatric blood
lead levels have been found in neighboring Southeast (SE) Asian countries due to other environmental
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lead exposures such as lead battery recycling and electronic waste (e-waste) (Gottsfeld and Pokhrel
2011). Some of these same exposures can be found throughout Vietnam. Therefore, it is important to
evaluate the current prevalence of elevated blood lead levels among children in Vietnam (Vietnews
2011). A range of environmental exposure sources are of increasing interest as it becomes clear that there
does not appear to be a safe level of lead exposure in children.
Children often suffer greater effects from lead exposure than adults do for a variety of reasons:
their intake of lead per unit of body weight is higher; they may be exposed throughout pregnancy; they
are more likely to engage in hand-to-mouth behaviors that increase their ingestion of dust and soil; they
are more likely to spend time in a single environment; they have greater potential for nutritional
deficiencies that can lead to increased absorption of lead; they have more years of future life and
potentially longer to develop consequences of exposures; and they tend to lack control over their
environment (ATSDR 2007). All of these factors, combined with the fact that their systems are still
developing, make them more vulnerable to the deleterious effects of lead.
There is a great deal of variation between countries in their approach to pediatric lead evaluation.
The US has a fairly comprehensive approach with specific screening criteria for children who are most
likely at risk (CDC 2002). Vietnam does not appear to have any form of routine surveillance in place,
even though there has been increasing awareness of at-risk children, particularly around lead recycling
and craft villages. I could not find any information in English medical literature or in discussion with
Vietnamese personnel such as physicians and environmental scientists regarding any form of lead
assessment or prevention programs in the country. There does not appear to be any public health
movement to remediate any of the current lead exposures.
The present research project was developed to help increase awareness and information about
lead in Vietnam. It used a cross-sectional study to gain better understanding of current lead exposures,
blood lead levels, and risk factors for lead exposure in Vietnamese children. It is hoped that this study
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will be instrumental in assessing whether children are currently at risk for lead-related diseases and may
be useful in making public health recommendations and determining the need for additional surveillance
in Vietnam.