Finally, features and finishes that characterize simple, vernacular buildings should be retained and preserved; in the process of removing hazards, there are usually reasonable options for their protection. Wholesale removal of historic trim, and other seemingly less important historic material, undermines a building's overall character and integrity and, thus, is never recommended.

For each historic property, features will vary in significance. As part of a survey of each historic property, a list of priorities should be made, in this order:

• Highly significant features and finishes that should always be protected and preserved;
• Significant features and finishes that should be carefully repaired or, if necessary, replaced in-kind or to match all visual qualities; and
• Non-significant or altered areas where removal, rigid enclosure, or replacement could occur.

This hierarchy gives an owner a working guide for making decisions about appropriate methods of removing lead paint.

II. Undertake a risk assessment of interior and exterior surfaces to determine hazards from lead and lead-based paint.

A licensed professional uses an x-ray fluorescence scanner to determine--without disturbing the surface--whether lead is present in underlying layers of paint. Photo: NPS files.

While it can be assumed that most historic housing contains lead-based paint, it cannot be assumed that it is causing a health risk and should be removed. The purpose of a risk assessment is to determine, through testing and evaluation, where hazards from lead warrant remedial action. Testing by a specialist can be done on paint, soil, or lead dust either on-site or in a laboratory using methods such as x-ray fluorescence (XRF) analyzers, chemicals, dust wipe tests, and atomic absorption spectroscopy. Risk assessments can be fairly low cost investigations of the location, condition, and severity of lead hazards found in house dust, soil, water, and deteriorating paint. Risk assessments will also address other sources of lead from hobbies, crockery, water, and the parents' work environment. A public health office should be able to provide names of certified risk assessors, paint inspectors, and testing laboratories. These services are critical when owners are seeking to implement measures to reduce suspected lead hazards in housing, day-care centers, or when extensive rehabilitations are planned.

The risk assessment should record:

• the paint's location
• the paint's condition
• lead content of paint and soil
• the type of surface
• (friction; accessible to children for chewing; impact)
• how much lead dust is actively present
• how the family uses and cares for the house
• the age of the occupants who might come into contact with lead paint.