Environmental Exposure to BPA: Bisphenol A
Occurrence In Waterways
Detection of bisphenol A in the environment is possible
due to its potential release during manufacturing although
the levels found in the environment are extremely low
and pose no known risk to humans, wildlife or the environment.
Levels of bisphenol A in the environment are currently
being monitored by industry and government authorities
in North America, Europe and Japan.
The trace amounts of bisphenol A that are sometimes
detected in waterways have not been shown to have an
adverse environmental impact. Additionally, the concentrations
of bisphenol A found in waterways are generally well
below the threshold concentrations for known ecotoxic
effects, such as those used to determine toxicity to
green algae, daphnids and fish.
Numerous publications have reported measured concentrations
of BPA in streams and rivers in Japan, Europe and the
United States. The median reported water concentrations
from 21 European and 13 United States studies are 0.016
and 0.5 micrograms/L respectively (Cousins et al, 2002).
In cases where individual concentration data are reported,
many samples have no detectable level of BPA.
A recent report from the U.S. Geological Survey provides
data on the occurrence of BPA (and numerous other substances)
in a large number of U.S. streams, most of which were
characterized as streams susceptible to contamination
(Kolpin et al, 2002). Approximately 60% of the streams
contained no detectable level of BPA (detection limit
0.09 micrograms/L), the median detected concentration
was 0.14 micrograms/L, and only 2 streams were reported
to contain BPA at levels above 1 microgram/L.
More recently, a Japanese study reported detectable
BPA in 67 of 124 water samples selected from "Water
Quality Monitoring" sites for downstream rivers.
The median concentration of BPA, where detected, was
0.01 micrograms/L and 95% of the samples contained less
than 0.24 micrograms/L of BPA (Japan Environment Agency).
In a 1996 study, the receiving waters upstream and
downstream of the five BPA manufacturing sites in the
U.S. had no detectable BPA at a 1 microgram/L detection
limit. In a follow-up 1997 study, the receiving waters
upstream and downstream of four of the five BPA manufacturing
sites and two processing sites had no detectable BPA
at a detection limit (quantification with confirmation)
of 1 microgram/L. The fifth manufacturing site had BPA
concentrations ranging from 2 to 8 micrograms/L upstream
and from 7 to 8 micrograms/L downstream. This facility's
discharge makes up a large percentage of the receiving
water flow during dry conditions, when samples were
collected. Some BPA was apparently present in the discharged
effluent and likely flowed back into the area where
the upstream samples were collected (Staples et al,