[MS90]

From the article, it doesn't sound like it's coming out of the drains. It sounds like chemicals are being released when they fill pipe sections with steam which then dissipates into the surrounding air.

The fumes exposure is probably just due to the person's proximity to the job site, not from a plumbing connection.

[ryanobjc]

See my sibling comment - it’s entirely possible for fumes to enter their work via plumbing.

So I’d really downgrade that “probably” - ambient outdoor exposure maybe, but the facts as presented better fits an indoor exposure during the day.