What precautions do we need to take in painting a house with paint that is mostly below (but some above) the legal definition of lead paint? Is the legal definition meaningful?
My wife and I bought a house last year. As the house was built in the 1920s, we expected it would have lead paint. We had an inspector come in and use x-ray fluorescence to detect the presence and levels of lead paint. The test showed about 15 surfaces out of about 115 tested met the legal definition of lead paint--1.0 or more mg/cm2
lead. The paint is generally well-maintained, but we want to repaint for aesthetic reasons. We will be doing this work ourselves.
The question is: How careful do we need to be about renovation procedures (ie, sanding) on surfaces that are below the legal threshold yet have measurable amounts of lead? Many of the rooms have a series of readings like 0.0, 0.3, 0.3, 0.1, 0.4, 0.7, 0.3. Will sanding these surfaces produce dangerous levels of lead dust? Very little sanding will be required to repaint. Would holding a vacuum up to the surface while sanding be sufficient? Do we need to buy a HEPA vac? Should we follow the new guidelines
for contractors working with lead paint: cordoning off rooms with plastic, covering the floors and all furniture with plastic, no sanding or scraping without hooded tools, total airflow control, disposable clothing and respirators?
The underlying question is how to interpret these various levels. Is 1.0 a meaningful cut-off? Is 0.3 mg/cm2
just the normal amount of lead that is in the environment? Or does it mean there is lead paint but not as bad as some lead paint? How bad is "not as bad?" Is 0.3 mg/cm2
going to give us a one-third case of lead poisoning? Will 0.5 produce lead poisoning only in the left hemisphere of our bodies? 50% chance of lead poisoning?
It bears noting that we have a toddler living in the house with us. I would rather be safe than sorry, but not sure if this level of care is needed since these surfaces do technically fall under the legal limit...