1) A healthy 2 y/o is seeing you for well child care. In assessing for her lead risk you ascertain that she is well and that she has no known contact with peeling paint or other sources of lead. What is your next step?
In NYC all children need to be screened for their risk of lead exposure starting at 6 months of age and then rescreened every 6-12 months through 6 years of age. In addition all 1 and 2 year olds, irrespective of lead risk, need to have their blood lead level tested annually.
To help screen for lead risk the NYC DOH has develop a lead risk assessment questionnaire containing 10 questions:
RECOMMENDED LEAD RISK ASSESSMENT QUESTIONS FOR PARENTS
1. Is your child between 9 and 36 months of age?
2. Have any of your children or their playmates ever had a high blood lead level?
3. Does your child live in, or regularly visit, an older home or other place with peeling or damaged paint?
4. Does your child live in, or regularly visit, an older home or other place that is being or was renovated within the last 12 months?
5. Does your child have any developmental delays, have hand-to-mouth behavior, or put non-food items, such as paint chips or soil, in their mouth?
6. Has your child moved to the US from or traveled to a foreign country where lead poisoning may be common?*
7. Does your family use products from other countries such as health remedies, spices, food, or pottery?
8. Does your child play near a heavily traveled highway, bridge, or elevated train where there is peeling paint?
9. Does your child come into contact with an adult whose job or hobby involves exposure to lead (e.g., bridge painting and repair, building demolition, home renovation and repair, automotive and electronics repair, furniture refinishing, working with firearms, and arts/crafts work involving ceramics, metals, and color pigments)?
10. Is your child enrolled in or planning to enroll in Medicaid or the NYC Early Intervention Program?†
*In descending order of frequency, lead poisoning has been found in NYC children emigrating from Haiti, Mexico, Pakistan, Bangladesh, Dominican Republic, India, Guyana, China, Liberia, Guinea, Ecuador, Jamaica, Albania, Senegal, Guatemala, Nigeria, Ghana, countries comprising former Yugoslavia, United Kingdom, Honduras, Israel, Togo, Sierra Leone, Ivory Coast, Trinidad and Tobago, United Arab Emirates, Georgia, Portugal, Suriname, Morocco, Afghanistan, Mauritania, Thailand, Uzbekistan, Canada, Nepal, El Salvador, and Gambia.
†Medicaid requires a blood lead test for children up to age 6 not previously tested. Enrollment in preschool/daycare and the Early Intervention Program both require BLL documentation.
If your patient’s parents answer yes to any of the questions then the children should have a blood lead test preformed. In addition foreign born children up to 17 years of age from high risk countries, such as the Dominican Republic, who have not had a previous blood lead level, should be tested.
2) You explain to the parents of your 2 year old patient that you will need to draw a blood lead level on their child. They ask you how their child would have acquired lead.
Lead can be ingested or inhaled and can be stored in bones. White house paint is the major source of lead poising in the US. Prior to 1955 white house paint was composed of 50% lead and 50% linseed oil. By 1955 most paint manufacturers voluntarily reduced lead to 1%. By 1971 it became federal law that paint could contain no more then 1% lead by weight. In 1971 this law was revised to reduce the amount of lead permissible in paint to 0.06%. An estimated 5 million tons of lead has been applied to homes in the form of lead paint. As the paint deteriorates, or during remodeling the lead is released as lead dust which can be ingested by children. Of note over 45% of New York State’s housing was built prior to 1955. Leaded paint is still occasionally used for non-residential use.
Another major source of lead is from leaded gasoline. Lead was phased out from gasoline in 1977, but prior to that approximately 30 million tons of lead was released into the environment from leaded gasoline. Soil around high traffic areas, especially around bridges and highways, are still contaminated with lead from leaded gasoline. Urban soil often contains in excess of 200ppm of lead. Acceptable lead levels in soil are less then 50 ppm.
Lead can also be ingested by children in their drinking water. Acidic water of low mineral content, hot water, or water which has been sitting for extended periods of time in pipes can leach lead from lead pipes and or lead solder used in the pipes.
Lead can also directly contaminate food. Root vegetables grown in soil with elevated lead levels, or leafy vegetables in areas of high lead levels all contain elevated lead. In addition storing food in leaded glass containers, ceramics from foreign countries with lead in the glaze, some foreign made aluminum cans or wrapping them in paper with lead containing ink can result in lead leaching into the food.
There are also certain hobbies or jobs that bring people into contact with lead which they can bring home on their clothing. There are also some foreign made folk remedies and cosmetics which contain lead. Recently there have been reports of toys made in China which have contained lead.
Lead toxicity affects almost every organ system, especially the CNS, PNS, kidney and blood. For every increase in lead level of 10 micrograms/dl in blood there has been shown to be a corresponding decrease in IQ by 4-7 points.
3) The parents of your 2 year old patient want to know why their 7 year old does not need to be tested for lead.
The peak risk for elevated lead is 12-36 months of age. Children are at increased risk at this age because they are mobile, they have hand to mouth behavior, they have rapidly developing organs, they have up to a five fold increase in lead absorption from their GI tracts as compared to adults, and they have a less developed blood brain barrier. In addition because toddlers are often picky eaters they may have iron, vitamin c or
Calcium deficiencies which lead to increased absorption of lead.
4) Your 2 year old patient’s lead comes back at 9, what follow up does she need and what symptoms do you expect to see.
All lead levels greater then or equal to 5 need to be monitored. The families with children with elevated lead levels need to be educated to reduce the children’s exposure to lead. They should have peeling paint repaired and wash hands, surfaces and anything else that the child puts in his or her mouth to remove the dust that may contain lead. They should make sure that no health remedies, cosmetics, spices, ceramics or toys which are made in foreign countries contain lead. They should use only cold water for drinking and cooking and let the water run for a few minutes in the morning to flush out the water which has been standing in the pipes overnight. They should wash any work clothes which might be contaminated with lead separately.
In addition you need to asses for adequate intake of Calcium, Vitamin C and iron.
If the lead level is 10-14 then in addition to the above steps the lead level needs to be reported to the NYC DOHMH within 24 hours by FAX.
If the lead level is 14-44 then in addition to the steps above the physician must perform a detailed environmental, developmental and nutritional history and physical exam and evaluate for iron deficiency. You should also consider an abdominal x-ray looking for paint chips. For leads of this level the NYC DOHMH will inspect the child’s home, order the landlord to perform repairs, refer the patient and their family to a safe house if necessary and refer all patients less then 36 months of age to early intervention.
Children with lead levels > 45 should be hospitalized for chelation therapy. Chelation only removes the lead which is in circulation. After chelation lead which has been stored in bones and other organs is released and the blood lead level rebounds often necessitating multiple rounds of chelation therapy. The NYC DOHMH should be notified of all admissions for lead poisoning by calling 212-676-6100.
All elevated leads should be followed as per NYC DOH protocol:
FOLLOW-UP BLOOD LEAD TEST SCHEDULES FOR CHILDREN
For Fingerstick BLLs ³5µg/dL12
Capillary Test Time Frame for Confirmatory
Result (µg/dL) Venous Test
5–9 3–6 months*
10–14 3 months†
15–44 1 week–1 month‡
³45 Immediately
For Venous BLLs ³> or equal to 5µg/dL12
Venous Early Follow-up Test
Venous Early F/U test Late F/U test
BLL (first 2-4 tests after ID) (after BLL begins to decline)
5–9 3–6 months* 6–12 months
10–14 3 months† 6–9 months
15–19 1–3 months† 3–6 months
20–24 1–3 months† 1–3 months
25–44 2 weeks–1 month 1 month
³45 or> As soon as possible Chelation with subsequent follow-up
* Recognize that a BLL of 5–9 may indicate lead exposure. If risk assessment indicates exposure is likely, consider retesting within 3 months to confirm BLL is not rising rapidly.
† Health care providers may choose to repeat BLLs within 1 month for patients newly identified with an elevated BLL to confirm that BLL is not rising rapidly.
‡ The higher the BLL, the sooner confirmatory venous testing should occur.
At a lead level of 9 your patient is most likely asymptomatic. There might be some subtle effect on IG which begins to occur at lead levels between 5-10. Effects on FEP and Vitamin D metabolism do not occur until lead levels of 10-20 and decrease in hemoglobin synthesis does not occur until lead levels closer to 40.
More apparent signs of lead toxicity such as frank anemia, nephropathy, abdominal pain and encephalopathy do not occur until lead levels well over 50. At lead levels of 100-150 death can occur.
Sources:
For the most up to date recommendation for lead poisoning prevention and management see the NYC DOHMH. Their most recent recommendations can be found on the NYC DOHMH website: www.nyc.gov/doh it is in Vol.26(3):15-22
Another good source for current recommendations is the CDC. The most current recommendations are
Center for Disease Control and Prevention. Preventing Lead Poisoning in Young Children. Atlanta, Ga:CDC:2005
A good article for management and screening as well as parental education
Schonfeld D, Needham D. Lead: A practical perspective. Contemporary Pediatrics.1994:11(5)64-96
A good article for the effects of and treatments for lead poisoning is
Piomelli S. Childhood Lead Poisoning. Pediatric clinics of North America.2002:49(12)
