Urinary arsenic levels are used as a measure of exposure. levels above 100 mcg/l of urine are of concern. convert this to ppb

Urine having high levels of Arsenic denotes greater exposure to the metal Arsenic and is dangerous for human health.

The levels of arsenic (As) that are considered to be of concern are greater than 100 mcg/L

We have to convert 100 mcg/L to ppb.

The conversion factor used here is 1 ppb = 1 mcg/L

Converting 100 mcg/L to ppb:

Therefore, Urinary arsenic levels greater than 100 ppb are considered to be concerning.