One source of lead exposure that needs to be considered is that from candles.
Candles are very popular and many people burn multiple candles on a regular basis.
Metal core wicks are often used, some of these may be lead based. Even zinc wicks may contain some lead. There is no reliable way of knowing if a metal core wick contains lead. Related Articles Emissions of lead and zinc from candles with metal-core wicks. Sci Total Environ.