The following is a redacted summary from the “CDC Recommendations for Lead Poisoning Prevention in Newly Arrived Refugee Children” Medical Provider Module.
Aim: To conduct blood lead testing on all newly arrived refugee children, providing nutritional evaluations and appropriate case management services.
Man’s use of lead dates back 5500 years and, courtesy of industrialization, lead is now found everywhere in our environment. Because of its durability and malleability, sheets of lead have been used to make water pipes, pewter vessels, paint, and other commercial products. A heavy metal, lead does not break down or decompose.
Childhood lead poisoning is one of the most common and preventable childhood health problems in the United States today. Enough is known about the sources and pathways of lead exposure and ways to limit exposure. The only accurate way to measure a child’s exposure to lead is by taking a blood sample and testing it for lead. While no safe blood level exists, a blood lead level (BLL) ≥ 5 µg/dL is defined as elevated — a level at which harmful health effects are known to occur.
Great strides have been taken through the years to reduce BLLs among young children in the United States. A reduction in lead hazards (such as leaded gasoline) and improved screening practices and policy initiatives has BLL in children aged 1-5 years continuing to decline in the United States (NHANES, 1999-2002 data: geometric mean BLL in the U.S. population for children aged 1-5 years was 1.9 µg/dL, and the national prevalence of elevated BLLs was 1.6%). [1]
There are, however, isolated communities of higher BLL. As many as 33.6% of children in one U.S. community had elevated BLLs.2 In addition, the risk for elevated BLLs remains high for certain populations — as many as 27% of newly arrived refugee children had elevated BLLs. [3]
Lead is a poison that affects almost every system in the body. Shortly after lead gets into the body, it travels in the blood to the soft tissues — the liver, the kidneys, … the brain. It is particularly harmful to the developing brain and nervous system of fetuses and young children. Children’s unique physiology and behavior can influence the extent of their exposure, leaving them at higher risk for the adverse health effects of lead.
- Children’s nervous systems are still developing
- Children have more hand-to-mouth activity
- as part of normal development, young children often place their hands and toys into their mouths. This activity is the most frequent cause of lead ingestion. If lead contaminated dust is found on the floor or a child’s toy, the child’s exposure is increased
- Children absorb more lead than adults in their gastrointestinal (GI) tract when exposed to lead
- per unit body weight, children drink more water, breathe more air, and consume more food than adults. Children absorb greater amounts of lead in food and beverages. Children absorb about 40% compared with adult’s absorption of 5-15%. 4
Lead has no known physiologic value to the human body and no safe lead level exists. And, lead poisoning for the most part is asymptomatic. The vast majority of those exposed may go undiagnosed and untreated. But the reality is that lead affects children in various ways:
- reductions in IQ and attention span, leading to learning disabilities
- behavioral problems (such as hyperactivity); associations have also been found between lead exposure and aggression and antisocial or delinquent behaviors
- impaired growth and hearing loss
- severe neurological problems such as seizures, coma, and even death caused by very high levels (higher than 70ug/dL)
These effects are more pronounced in the refugee population.
From the mid-1970s until the mid-1990s at least three-quarters of refugees coming to the United States were from the former Soviet Union or Southeast Asia. Now refugees are admitted from some 60 locations around the world. Specifically, the percentage of refugees from Europe has decreased while the percentage of refugees from Africa has increased from 9 to 35%.
Childhood lead poisoning is a problem worldwide. In other parts of the world, predominant sources of lead are very different from those lead sources in the United States.
- leaded gasoline is still widely used in many countries and contributes to elevated BLLs, especially in urban children
- poorly glazed pottery causes high lead levels in food, which can be the most prominent source of lead in some areas, such as parts of Latin America
- point industrial sources, such as smelters, may dramatically increase lead levels in air and soil in parts of the world where environmental controls have not been effectively implemented, such as in Eastern Europe
- lead contamination from cottage industries that recycle lead (often in backyards) is a problem in Central America and elsewhere
- additional sources of lead contamination include flour mills, medications and, cosmetics and consumer products
Newly arrived refugee children are twice as likely as U.S. children to have elevated BLLs. Some sub-populations of refugee children are 12-14.5 times more likely to have elevated BLLs. [3]
Even though refugees may be exposed to lead prior to arriving into the United States, data suggest that refugee children are also exposed to lead in this country. And for some children, living in the United States gives them their first exposure to lead. [5]
Several risk factors exist for elevated BLLs in children, some of which are more specific to the refugee population.
The most common risk factor for ALL children is living in an older home, specifically those homes that were built before 1950 and are in disrepair
Also, a known risk factor is the visual presence of lead hazards such as peeling and chipping paint on the housing exterior
However, in the refugee population:
- some cultural practices and behaviors could increase the chance of ingesting lead (such as eating off the floor). Traditional medicines and cosmetics from the home country may also contain lead
- an overall lack of awareness about the dangers of lead and the need to protect children from known lead hazards makes the refugee population more vulnerable
- a compromised nutritional status – the evidence of chronic and acute malnutrition – is a risk factor
Malnutrition is common in refugee populations.6 Anemia can enhance lead absorption and thus can increase risk for elevated BLLs, even in housing with minimal lead exposure hazards.
It is important to note: Children who mouth or eat non-food items, especially soil (common among certain refugee populations) are at risk for lead poisoning, regardless of the age of their housing.
Lead Exposure in the United States
Because the primary risk factor for lead poisoning in the United States is older housing, most lead hazards come from lead paint chips that have been ground into tiny bits. These tiny bits of lead become part of the dust and soil in and around homes.
Although children may be exposed to lead from paint directly by ingesting paint chips, they are more commonly exposed by ingesting house dust or soil contaminated by leaded paint as part of normal hand-to-mouth behavior.
Lead contamination of dust or soil occurs when leaded paint deteriorates or is subject to friction or abrasion (as on window sashes). In addition, lead can be dispersed when paint is disturbed during demolition, remodeling, paint removal, or preparation of painted surfaces for repainting.
Lead was used widely in paint through the 1940s. Although lead use declined during the 1950s and 1960s, and lead was banned from residential house paint in 1978, lead remains a hazard in homes built before the ban, especially in homes built before 1950.
According to the, nearly 38 million housing units contain lead-based paint (U.S. Department of Housing and Urban Development). Of the 38 million, 24 million housing units (25% of the nation’s housing) have significant lead-based paint hazards (such as deteriorating lead paint or lead-contaminated dust).
In addition, 1.2 million homes with significant lead-based paint hazards housed low-income families with children younger than 6 years of age. Refugee families are often resettled into older housing because of the affordability of these units.
A child’s environment is full of lead, from lead in paint chips that makes its way into the dust and onto toys. Contamination of soil and exterior dust has been linked to sources such as lead smelters, fall-out from past use of leaded gasoline, and weathering of exterior leaded paint. Soil located next to dwellings typically has higher lead content than soil sampled from other locations in a yard. Potentially hazardous levels of lead in soil are not uncommon.
Although lead in tap water contributes to children’s lead body burden, it is seldom the sole cause of elevated blood lead levels. Lead in tap water usually is from the corrosion of lead-containing materials found in water distribution systems and household plumbing. Exposure to lead in tap water has been reduced by measures taken during the last two decades under the requirements of the 1986 and 1996 amendments to the Safe Drinking Water Act and a subsequent U.S. EPA regulation (the Lead and Copper Rule).
Except near the area of point sources — such as smelters and battery manufacturing plants — inhalation of airborne lead is now a minor exposure pathway for individual children in the United States.
During the 1980s, the quantity of lead in the U.S. diet decreased markedly due to restricted use of lead-soldered side-seam cans and the phasing out of lead as an additive in gasoline. Lead in foods comes from several additional sources (see http://www.cdc.gov/nceh/lead):
- soil in which the plant is grown
- air and rain
- food processing (including lead leaching from some types of metal cans described above)
- contact with lead solder or ceramic vessels used to store the food
- contact with lead dusts in the home
THE NEWLY ARRIVED REFUGEE
Federal standards stipulate that a refugee medical screening take place within 90 days after a refugee’s arrival in the United States. The contents of the screening vary from state to state. Most do not have a BLL screening protocol for refugee children. CDC recommends blood lead testing of children within 90 days of arriving into the United States so treatment can be provided if necessary.
The American Academy of Pediatrics also recommends testing children who have emigrated from other countries where lead poisoning is prevalent.7
Studies have shown that age is not a significant risk factor for elevated BLLs among refugee children. Although the risk for lead exposure among children older than 6 years may be the result of lead exposure in their country of origin, many of the prevailing health, social, and economic burdens accompany the children to the United States thus suggesting the value of screening ALL refugee children at time of arrival.
Unless contamination of capillary samples can be prevented, lead levels should be measured on venous samples. Contamination of capillary specimens obtained by finger prick can be minimized if trained personnel follow proper techniques.
Within 3 to 6 months after refugee children are placed in permanent residences, repeat blood lead testing of all refugee children aged 6 months to 6 years. Also test older children, if warranted, regardless of initial test results.
The rationale to test refugee children again at 3 to 6 months is from a 2005 New Hampshire case study5 demonstrating that the majority of the refugee children do not have elevated BLLs upon arrival into the United States. But the follow-up screening, conducted on an average of 60-90 days after placement or after the children settled into their permanent residences, revealed that these New Hampshire refugee children had elevated BLLs ranging from 11 to 72 µg/dL.
This repeat blood lead test should be considered a “medical necessity,” regardless of the initial test result.
The refugee status for most of the children entitles them to Medicaid and Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) services, and other social services for at least 8 months after their resettlement, regardless of family financial status.
Upon United States arrival, all refugee children should have nutritional evaluations performed and should be provided with appropriate nutritional and vitamin supplements as indicated.
Pre-existing health burdens such as chronic malnutrition, along with cultural, language, and economic barriers, compound refugee children’s risk for lead poisoning.
For example, iron deficiency, prevalent among refugee children, increases lead absorption through the gastrointestinal tract.
At a minimum, the nutritional evaluation should have an evaluation of the children’s iron status, including a hemoglobin/hematocrit, and one or more of the following:
- mean corpuscular volume (MCV) combined with red cell distribution width (RDW)
- ferritin
- transferring saturation
- reticulocyte hemoglobin content
Additionally, a WIC referral for nutritional benefits should be provided to the family.
Medical interventions and treatments vary depending on the confirmed blood lead level.
A confirmed elevated BLL is one venous test or two elevated capillaries within 12 weeks/80 days of each other (see www.cdc.gov/nceh/lead for specific information about medical, environmental, nutritional, developmental, and educational interventions).
Another important note: While chelation therapy is considered a mainstay in the medical management of children with BLLs > 45µg/dL, it should be used with caution. Prior to using chelation agents consult with an expert in the management of lead chemotherapy. (Note: Endrate disodium (Na2EDTA) should NEVER be used for treatment of lead poisoning because it may induce fatal hypocalcemia and tetany.)
Neurodevelopmental monitoring should continue long after the child’s BLL has been reduced, as many deficits will not manifest themselves until after a child starts school. Because developmental history and testing at the time of an elevated BLL usually will not identify lead-case problems, a child’s elevated BLL history should be part of his permanent record. In the absence of empirical evidence, it is reasonable to suggest that such children would benefit from the types of interventions shown to be effective in facilitating the neurodevelopment of other groups of children who had idiopathic neurodevelopmental problems or who were at increased risk for such problems, such as low birth-weight infants.
CDC Tool Kit
Lead Poisoning Prevention in Newly Arrived Refugee Children: Tool Kit
Other Resources
- State and local childhood lead poisoning prevention programs
- provides comprehensive childhood lead poisoning prevention efforts in 40 state and local programs, funded by CDC.
- CDC’s Lead Poisoning Prevention Program
- provides leadership to state and local health departments in developing comprehensive programs to combat childhood lead poisoning.
- Office of Refugee Resettlement
- plans, develops and directs implementation of a comprehensive program for domestic refugee and entrant resettlement assistance. The Office monitors and evaluates the performance of states and other public and private agencies in administering these programs and supports actions to improve them.
- American Academy of Pediatrics
- provides policy statements on lead screening and treatment.
References
- CDC. Blood lead levels — United States, 1999–2002. MMWR 2005;54(20):513-16.
- Dignam TA, Evens A, Eduardo E, et al. High intensity targeted screening for elevated blood lead levels among children in 2 inner-city Chicago communities. Am J Public Health. 2004;94(11):1945-51.
- Geltman PL, Brown MJ, Cochran J. Lead poisoning among refugee children resettled in Massachusetts, 1995 to 1999. Pediatrics. 2001;50:457-59.
- Ziegler EE, Edwards BB, Jensen RL, et al. Absorption and retention of lead by infants. Pediatr Res. 1978;12:29-34.
- CDC. Elevated blood lead levels in refugee children – New Hampshire, 2003-2004. MMWR. 2005;54(2);42 – 46.
- United Nations System/Standing Committee on Nutrition. Nutrition information in crisis situations. Geneva, Switzerland: Secretariat of the UNS/SCN; May 2004. Report no. 2.
- American Academy of Pediatrics. Screening for elevated blood lead levels. Pediatrics. 1998;101(6):1072 – 1078.
