It was one of the 'best' exterior and trim paints available for a time. Not easy to remove from old window sills or concrete ledges. It only gets removed somew

It was one of the 'best' exterior and trim paints available for a time. Not easy to remove from old window sills or concrete ledges. It only gets removed somewhat during necessary window and door replacements. So it is ubiquitous in older houses and flats. Doesn't matter if it is 1 million USD, the lead will be somewhere if it is old enough. Particularly attics and basements, or anywhere with grindy old doors or windows -- not safe for children. The plumbing also has lead, either through lead pipes directly or iron pipes with leaded solder or other high lead content.