Preventing Lead Poisoning in Young Children: Chapter 8
- Table of Contents
- Chapter 1. Introduction
- Chapter 2. Background
- Chapter 3. Sources and Pathways of Lead Exposure
- Chapter 4. The Role of the Pediatric Health-Care Provider
- Chapter 5. The Role of State and Local Public Agencies
- Chapter 6. Screening
- Chapter 7. Diagnostic Evaluation and Medical Management of Children with Blood Lead Levels > or = to 20 µg/dL
- Chapter 8. Management of Lead Hazards in the Environment of the Individual Child
- Chapter 9. Management of Lead Hazards in the Community
- Appendix I. Capillary Sampling Protocol
- Appendix II. Summary for the Pediatric Health-Care Provider
Eradicating childhood lead poisoning requires a long-term active program of primary lead-poisoning prevention, including abatement of lead-based paint hazards in homes, day-care centers, and other places where young children play and live. For the child who is lead poisoned, however, efficient and effective interventions are needed as quickly as possible. Abatement means making the source of lead inaccessible to the child.
Lead-based paint is the most common source of high-dose lead poisoning. Complete abatement of lead-based paint means eliminating all lead- based paint in a housing unit as a source of lead for the child, either by removing the paint or by using permanent barriers. Complete abatement of the lead hazards in the child's environment is the most effective and only certain way to prevent further damage. Complete abatement is expensive, but once a dwelling is abated, many generations of children may live in that home and reap the benefits. Unfortunately, complete abatement may not always be possible, and shorter term, preventive maintenance procedures may have to be undertaken to minimize the potential for further damage.
Lead-based paint is rarely completely abated in many of the largest childhood lead poisoning prevention programs. Instead, various degrees of incomplete abatement—designed to eliminate the worst hazards and prevent near-term exposures—are conducted. Development of cost- effective, safe, simple, and widely applicable methods of complete paint abatement is a high priority.
Whether complete abatement or preventive maintenance is done, persons performing the work should be knowledgeable of the hazards of lead to themselves, to children, and to the environment. They should be trained in the proper procedures for abatement and preventive maintenance, since improperly performed work can actually increase the hazards to the child.
Each situation in which a child gets poisoned is unique and must be evaluated by a person or team of persons skilled and knowledgeable about lead poisoning, hazard identification, and interventions to reduce lead exposure, including abatement of lead-based paint in housing. Childhood lead poisoning prevention programs need to work closely with other relevant agencies (for example, housing and environmental agencies) to ensure that the quickest and most effective approach is taken to remediation the environments of poisoned children.
The 1985 CDC statement on Preventing Lead Poisoning in Young Children set the level for environmental intervention at 25 µg/dL. In this new statement CDC recommends environmental intervention for children with blood lead levels of > or = to 20 µg/dL, or of > or = to 15 µg/dL that persist. Where resources are limited, however, individual environmental intervention must first focus on those children with the highest blood lead levels. CDC also recommends that environmental interventions be directed at primary prevention of lead poisoning in communities with a large number or percentage of children with blood lead levels > or = to 10 µg/dL (Chapter 9).
The Department of Housing and Urban Development has issued Lead-Based Paint Interim Guidelines for Hazard Identification and Abatement in Public and Indian Housing, hereafter called the HUD Guidelines (HUD, 1990, also published in the Federal Register 55FR14556). (The worker protection guidance was subsequently revised and published in the Federal Register, 55FR39873.) This document is referenced frequently in this Chapter because it contains the most comprehensive information on identifying and abating lead-based paint hazards available. It is not expected that every childhood lead poisoning prevention program or every homeowner will follow the guidelines completely. These guidelines were written for lead hazards in public and Indian housing, particularly for use during comprehensive modernization programs. Such programs, carried out when the property is vacant and in multiple units at one time, offer opportunities for very thorough and complete abatements. Most abatement of lead-based paint in the private sector does not occur in such a context. In the private sector, abatement is generally done in occupied housing scattered throughout an area, often with limited resources. In the context of this Chapter, the HUD guidelines are an information source on identifying and abating hazards.
Environmental case management includes a number of actions prescribed for a child with lead poisoning. Ideally, environmental case management should be conducted by a team of professionals in public health, environmental activities, medical management, and social management. A team approach to intervention will help ensure that followup is timely and effective. The management team may need to solve many related problems, such as whether to investigate supplemental addresses, where to find temporary alternative housing, and how to use community resources to assist the family in dealing with the lead-poisoned child.
A team approach to case management is most effective when all team members:
- Demonstrate professionalism.
- Show genuine concern for the poisoned child and family.
- Support other team members.
- Use similar terms, descriptions, and reference points to communicate with the child's family.
- Meet specific time frames for followup.
- Reinforce education of the family at every encounter.
Time Frames for Investigations and Interventions
The following guidelines describe the maximum time within which environmental interventions should be implemented. All children with blood lead levels > or = to 20 µg/dL should have environmental interventions conducted as quickly as possible. Children with blood lead levels > or = to 45 µg/dL require prompt chelation therapy. The homes of these children must be remediated before they are allowed to return.
Blood lead levels > or = to 70 µg/dL. Children with blood lead levels above 69 µg/dL constitute a medical emergency and must be hospitalized immediately. They are at highest risk for severe, permanent neurologic damage due to lead exposure and must be given highest priority for followup. Environmental investigation and intervention should be started within 24-48 hours and should include the child's home and potential sites of exposure, such as a relative's home or a day-care center. The homes of these children must be remediated before they are allowed to return.
Blood lead levels between 45 and 69 µg/dL. These children can be given a slightly lower intervention priority than the children classified as medical emergencies. Environmental investigation and intervention should begin within 5 working days and should include the same components as for children with higher blood lead levels. The homes of these children must be remediated before they are allowed to return.
Blood lead levels between 20 and 44 µg/dL. Environmental investigation and intervention should begin within 10 working days. Since many of these children will not be hospitalized and since allowing exposures to continue might lead to further increases in blood lead levels, environmental interventions for these children should be conducted as quickly as possible.
Blood lead levels between 15 and 19 µg/dL. Environmental investigation and intervention for children at this level should be based upon program resources and the ability of program staff to respond. At a minimum, these children and their families should have education regarding lead poisoning. If blood lead levels > or = to 15 µg/dL persist, environmental intervention should be made where possible—including assisting the parents in locating potential sources of lead contamination in and around the home and instructing them about how to reduce the risk of lead contamination. If resources permit, a full environmental inspection for lead-based paint should be done for such children.
Although full environmental investigation and abatement is not recommended as part of the management of children with blood lead levels below 15 µg/dL, the identification and reduction of lead hazards in all high-risk housing is an important primary prevention measure (Chapter 9).
Educating Parents about Lead Poisoning
The parents of all lead-poisoned children should be educated about lead poisoning. In communities with a high incidence of lead poisoning, community wide educational efforts should be considered. These efforts should provide information similar to that in the anticipatory guidance provided by pediatric health care providers. Information provided should include:
- Causes and effects of lead poisoning.
- Relationship of the child's blood lead level to the potential for adverse health effects.
- Need for followup blood lead testing of the child.
- The child's possible sources of lead intake and practical means for reducing and eliminating these sources.
- Role of nutrition in decreasing lead absorption.
- Resources where parents can get further information (addresses and telephone numbers of local health-care providers or public health agencies).
Ideally, this information should be provided during a face-to-face meeting with the parents. When local resources are limited, however, written material (in an appropriate language) may be mailed to the child's family. Educating parents about lead poisoning is further discussed in Chapter 4.
Investigating the Environment and Communicating the Results
The technical aspects of inspecting a home for lead-based paint are discussed below. In general, an investigation of the environment of a lead poisoned child should include the following steps:
- Determine the most likely sources of high-dose exposure to lead.
- Investigate the child's home to identify possible sources of lead. Include both the interior and exterior environment and give special attention to painted surfaces, dust, soil, and water. (Details on how to test for lead-based paint are in the next section.)
- Advise parents and caretakers about identified and potential sources of lead and ways to reduce exposure.
- In cases in which the parent does not own the home, notify the property owner immediately that a child residing on the property has lead poisoning. Discuss the results of the environmental investigation and the abatement interventions required with the property owner. Emphasize the importance of prompt abatement. When a child with a medical emergency from lead poisoning is identified, an immediate, face-to-face meeting with the property owner may best demonstrate the need for emergency intervention.
- Advise parents and property owners that no residents or personal belongings should remain in the home during abatement.
- Monitor the effectiveness and timeliness of abatement procedures closely.
- Coordinate environmental activities with those of other professionals, including the health-care providers and persons responsible for public health and social management. A team approach to intervention will help provide a timely and effective followup.
Emergency Measures to Reduce Lead Exposure
The first phase of environmental intervention may be to use short-term emergency interventions to temporarily reduce lead hazards. As soon as a blood lead level > or = to 20 µg/dL (or, if resources permit, > or = to 15 µg/dL) is confirmed, parents should be advised of the hazards of lead-based paint and lead dust. They should be told not to attempt abatement themselves improper abatement will most likely increase lead dust levels in the home and create additional, more severe exposure for the child. The temporary nature of interventions other than abatement should be emphasized.
When the source of lead is paint and paint-contaminated dust, parents can be instructed to stabilize the paint, wet-mop all floors, and wet-clean window sills and window wells at least twice per week. Cleaners high in phosphates appear to work particularly well. Sponges and rags used in this cleaning should be used for no other purpose. In particular, they should not be used to wash dishes or clean eating- or food-preparation surfaces, since dangerous contamination could result. Children's hands should be washed regularly, particularly before eating. Toys and pacifiers that are mouthed should be washed at least daily. Cribs and playpens should be moved away from chipping or peeling paint; furniture can be placed in front of areas that are not intact to make them less accessible. Dry sweeping of dust should be avoided, because it will stir up and spread the dust. Other measures to reduce lead exposure are discussed in Chapter 4.
Long-Term Measures to Reduce Lead Exposure
The next phase of environmental intervention involves long-term hazard reduction. If the source of lead is paint and paint-contaminated dust, the lead hazards are permanently abated only when all lead-based paint is completely removed or otherwise made permanently inaccessible. Less extensive practices, which are commonly used by childhood lead poisoning prevention programs, may be called "long term abatement." Certain maintenance procedures (for example, frequent cleaning and keeping walls freshly painted) may be classified as "preventive maintenance," but in general these procedures offer no absolute assurance of safety. In cases other than "permanent abatement," how long the hazard will remain under control depends on such factors as the quality of the workmanship, the thoroughness of the procedure, the soundness of the underlying structure, and the condition of the plumbing and roof. Moisture from leaky pipes or roofs can quickly cause paint that was smooth and intact to blister and scale, generating hazardous levels of lead dust. Except in unusual situations (such as in the case of housing that is not likely to be viable for more than a couple of years or when no alternative housing is available), temporary measures to reduce exposure should not be a substitute for abatement or an excuse for delaying abatement.
Technical aspects of lead-based paint abatement are discussed below.
Evaluating Intervention Activities
The effectiveness of any intervention for a lead-poisoned child should be evaluated by its impact on the child's blood lead level. Measurement of environmental lead levels may also be helpful.
Assessing the Lead Problem in the Child's Community
If a number of children are identified as being lead-poisoned in a community, communitywide interventions as described in Chapter 9 should be considered.
NOTE: Remodeling or repainting homes with lead-based paint should be considered just as hazardous as abatement. Whenever lead-based paint must be disturbed by sanding, scraping, heating, or other forms of abrasion, the same precautions should be taken for remodeling or repainting as for abatement itself.
Inspection and testing
Several methods are available for determining the lead content of paint. These include XRF, wet chemical methods, and chemical spot tests. Although XRF analyzers are convenient, instruments available at the present time have limitations. A study by the National Institute of Standards and Technology (NIST, 1989) indicated possible substrate errors in the direct- reading XRF's of as much as + or - 2 mg/cm2. These errors were caused by differences in base materials in walls and trim. (At very high readings, for example, above 3 mg/cm2, this error has no practical significance). The spectrum analyzer, while considerably more expensive than the direct reader, provided much more accurate results. Only fully trained and experienced personnel should use XRF analyzers.
Wet chemical methods of analysis must be used if an XRF machine is not available or if it produces ambiguous results. Wet chemical methods require that a paint chip sample with all layers of paint on the surface be sent to a laboratory for analysis. Wet chemical analysis has two major disadvantages—results are not available immediately, and it is expensive.
Like XRF, chemical spot tests are performed on-site. A scratch is made through all layers of paint, and a chemical is placed on the scratch. If the scratch turns certain colors, further evaluation is needed. Chemical spot tests are qualitative, not quantitative, and the interpretation of the results is subjective. These tests are being refined and evaluated as to their safety, accuracy, and reliability.
Further information on proper testing procedures for lead-based paint is in the NIST study report and the HUD Guidelines.
The 1985 CDC statement on lead recommended an XRF value of 0.7 mg/cm2 as the maximum level of lead in paint in a residence. The HUD standard, mandated by Congress, is 1.0 mg/cm2. Several states have established their own XRF standards for lead in paint; these standards range from 0.7 mg/cm2 to 1.2 mg/cm2. The HUD document and some state regulations use a standard of 0.5% lead by weight for laboratory analysis.
Lead in paint should always be considered a "potential" hazard. An immediate lead hazard exists when lead-based paint is: 1) chipping, peeling or flaking; 2) is chalking, thereby producing lead dust; 3) is on a part of a window which is abraded through the opening and closing of the window; 4) is on any surface which is walked on (like floors) or otherwise abraded; 5) can be mouthed by a child (for example, window sills); or 6) is disturbed by repainting or remodeling. A potential lead hazard can easily become an immediate hazard through natural aging, plumbing or roof leaks, or the paint being disturbed. All lead-based paint exceeding the action level should, therefore, be abated whenever possible. Otherwise, complicated records must be kept of unabated surfaces, and those surfaces must be inspected frequently to make certain that they have not become immediate hazards.
When inspecting for lead-based paint hazards, care must be taken to evaluate all types of surfaces, including walls, ceilings, doors and windows, trim and jambs, woodwork, stairway components, porch components, garages, sheds, fences, play equipment, and any other structures on the premises. Because of legal requirements in some areas, it may be necessary to test every surface that may be painted with lead paint (that is, every window, every door, every piece of trim, etc.). Often, however, abatement decisions can be made without this costly and time-consuming approach. Even with an XRF, a full inspection of all surfaces in an average home may take 4 hours or more. Sometimes, extrapolating XRF results to untested surfaces may make sense. Such extrapolation, however, should only be used for positive results. For example, if test results for one window are positive for lead, it is safe to assume that all similar windows are painted with lead-based paint; if test results for one window are negative, it is not safe to assume that no windows have lead-based paint.
Recent studies have indicated that many children are poisoned by lead-contaminated dust ingested through normal hand-to-mouth activity. This dust can come from lead contaminated soil that is tracked into the home on shoes or from the clothes of a parent who works with lead. However, the most common source of lead dust in the average old house is lead-based paint. Some believe that the level of lead dust in a house can be used as a measure of the severity of the immediate hazard.
Proper abatement includes the following steps:
- Proper training of all workers involved in the abatement.
- Protecting those workers whenever they are in the abatement area.
- Containing lead-bearing dust and debris.
- Replacing, encapsulating, or removing lead-based paint.
- Cleaning the abatement area thoroughly.
- Disposing of abatement debris properly.
- Inspecting to make certain the property is ready for reoccupancy.
Abatement should never be attempted by untrained parents, property owners, or contractors. The property owner's responsibility is not met until all the above steps have been completed.
Preparation: Just prior to abatement, all personal belongings, movable furniture, and drapes should be removed from the abatement area. In homes with deteriorated lead-based paint, furniture may be highly contaminated with lead dust. It is recommended that badly soiled carpets and drapes be discarded because of the difficulty of removing lead from them. Furniture should be cleaned before it is returned to the abated dwelling or it should be replaced. Wood, metal, glass and plastic surfaces should be washed with a high phosphate detergent. If possible, all upholstered furniture, carpets, drapes, and bare surfaces should be vacuumed with a High Efficiency Particle Accumulator (HEPA).
Precautions: Residents and their belongings should remain out of their homes during abatement. Under no circumstances should children and pregnant women be allowed to enter the dwelling unit during the abatement because abatement can generate large quantities of hazardous lead dust.
Training: All workers involved in a lead abatement project should be properly trained in the following: health effects of lead; proper procedures for worker protection, including procedures for personal hygiene and for wearing and caring for respirators; containment of an abatement project; various methods for abating lead-based paint and the safety and environmental hazards involved with each; and procedures for transporting and disposing of abatement debris properly.
Worker protection: All workers on a lead abatement project and their families must be protected from the hazardous lead dust that will be generated. The minimum acceptable protection would be coveralls (preferably disposable); shoe coverings; hair covering; gloves; goggles; and a properly fitted, negative-pressure, half-mask respirator with a HEPA filter. Other, more protective respirators may be needed to protect from hazards such as organic vapors. If the abatement methods used would generate significant quantities of lead dust or organic vapors, workers must wear more protective respirators, such as supplied air-respirators.
The potential hazard to workers of lead dust ingestion is as significant, if not more significant, than inhalation. Workers must not eat, drink, or smoke on the job; and hands and face must be washed before breaks and at the end of the day. On-sight showers should, if possible, be provided. If on-site showers are not available, workers must shower and wash their hair immediately upon returning home. They must be careful not to carry hazardous levels of lead dust home on their bodies, shoes, or clothing. Therefore, work clothes should not be worn home; either workers should wear protective work clothes instead of street clothes at the worksite or they should wear protective garments over their street clothes. Work clothes should be disposed of or laundered by the employer to prevent the contamination of automobiles, homes, etc. with dust; lead-contaminated clothing should be handled with care and should not be laundered with other clothing of the worker or his family.
Note: The Chapter in the HUD guidelines on worker protection was revised and published separately in the Federal Register on September 28, 1990 (55FR39873).
Containment: The work area should be contained with plastic (6 mil) to protect other living areas, yards, heating and ventilation systems, etc. from contamination. All nonmovable furnishings, such as counters, cabinets, and radiators should be covered with plastic. All floors should also be covered with plastic to prevent lead dust from being deposited in cracks and crevices and from being ground into the surface during the abatement.
Abatement: Abatement methods fall into three categories: 1) replacement, 2) encapsulation or enclosure, and 3) paint removal. These categories are discussed in more detail as follows:
Replacement: Removing the building component (such as a window, door, or baseboard) and replacing it with a new one.
Encapsulation: Covering a lead-painted surface with a material that will effectively prevent access to the lead-based paint and that will also prevent lead-bearing dust from that surface from entering the living environment.
Paint Removal: Stripping paint by heat, chemical, or mechanical means. This can be done either on-site or at the premises of a chemical stripping firm.
Certain methods of removing lead-based paint may be particularly hazardous to both the worker and the building occupants and may be banned in some areas. They are—
- Removing paint with an open-flame torch or other heating device that operates at temperatures likely to volatilize lead (the melting point of lead is 621°F).
- Machine sanding surfaces with lead-based paint.
- Sand blasting lead-based paint, except when the equipment is fitted with a vacuum device that prevents the dispersal of the debris.
- Uncontained hydro-blasting.
- Using chemical strippers containing methylene chloride. Methylene chloride is extremely toxic and protecting workers from exposure to this chemical is difficult.
If possible, all surfaces painted with lead-based paint should be abated by replacement, encapsulation, or paint removal. Ordinary paint is never an appropriate encapsulant; it is only part of a temporary maintenance procedure. Encapsulation materials should be durable and, where possible, affixed with both fasteners and adhesive. Paint-like coatings should be used with caution. Only coatings and adhesives that are proven to be safe and effective should be used. Any material that will eventually chip, peel, or flake upon aging or from water damage is not appropriate.
Paint removal is potentially the most hazardous abatement method because considerable amounts of lead dust and lead residue are generated. Paint removal from porous surfaces, such as wood or concrete, always leaves significant amounts of lead residue. This residue may not be visible and removing it requires extremely vigorous cleaning procedures (alternating washing with a high phosphate detergent and HEPA vacuuming (see below)). Painting over this residue can lead to lead dust problems when this paint begins to deteriorate or when it is abraded. Of particular concern are friction surfaces, such as window and door jambs.
Workers using any method that generates large volumes of dust or fumes should use caution. Such methods increase the difficulty of worker protection and the likelihood that hazardous levels of lead-bearing dust will remain in the dwelling unit or be deposited in the soil surrounding the home. Demolishing older structures with lead-based paint likewise can result in deposition of lead-bearing dust into the soil or on neighboring property, and dust suppression techniques should be used.
Clean-Up: All lead abatement activity is likely to generate quantities of hazardous lead dust. Unless this dust is properly cleaned, the dwelling unit will be more hazardous after abatement than it was before. This dust is difficult to remove. Daily clean-up, consisting of misting debris with water, carefully sweeping it, and placing it in double 4-mil or 6-mil plastic bags, is necessary to minimize the risk to workers of accumulated lead dust.
After abatement and before repainting, all surfaces in the dwelling must be thoroughly vacuumed with a HEPA vacuum; wet washed, preferably with a high phosphate detergent such as tri-sodium phosphate; and then vacuumed again. The property should be visually inspected before being repainted. The inspector should ascertain that all surfaces covered with lead-based paint have been abated and that no visible dust or debris remains on site.
Several states have adopted a post-abatement dust standard which has been included in the HUD Guidelines. This standard was set mainly on the basis of practicality rather than a health or risk assessment, and further research is needed on the adequacy and appropriateness of that standard. The standard allows the following maximum levels of lead in dust:
|Window Sills||500 µg/ft2|
|Window Wells||800 µg/ft2|
Inspectors and persons collecting dust samples and laboratories measuring dust lead levels should be thoroughly familiar with the recommended sampling and analysis protocols for dust in the HUD Guidelines.
After the inspection, abated surfaces should be repainted, if appropriate. Wooden floors should receive a coat of deck enamel or urethane, concrete floors should be sealed with deck enamel, and linoleum or tile floors should be waxed. Sealing the floors will bind any remaining dust particles and enable the occupants to clean those surfaces easily.
Disposal: Certain wastes from a lead-based paint abatement project, either liquid or solid, may be classified as hazardous. If so, they will have to be treated as such and handled by a licensed transporter or treatment firm. In any case, all debris from an abatement project, whether classified as hazardous or not, must be contained and transported in such a way as to prevent the dispersal of lead bearing dust, chips, or liquid into the environment. Lead debris should never be sent to a solid waste incinerator, a disposal method that disperses lead into the air.
HUD (Department of Housing and Urban Development). Comprehensive and workable plan for the abatement of lead-based paint in privately owned housing: report to Congress. Washington (DC): HUD, 1990.
NIST (National Institute for Standards and Technology). Methods for measuring lead concentrations in paint films. Washington (DC): NIST, 1989.