Whilst the adverse effects
of tetrachloroethylene (PCE) and other solvents on mental health are well
documented in exposed adults, there are limited data linking early-life
exposure to mental health issues later in life. In the present study,
published in Environmental Health,
Ann Aschengrau and
colleagues show that early-life exposure to PCE-contaminated drinking water
is  associated with a greater risk of developing both bipolar disorder and
post-traumatic stress disorder. 

From the late 1960s to early
1980, public water companies in the Cape Cod region of Massachusetts, USA,
installed vinyl-lined (VL) asbestos-cement (AC) water pipes to help combat
alkalinity problems. More than a decade passed before the authorities became
aware that PCE was leaching from these pipes into drinking water, with levels
of PCE ranging from 1.5 to 7,750 μg/L. Today, the maximum contaminant level for
PCE is set at 5 μg/L. 

The problem had stemmed from
the way the VL/AC pipes were manufactured. The liner was applied by spraying a
mixture of vinyl resin and PCE onto the inner pipe surface, and given 48 hours
to dry. It was assumed that this would allow sufficient time for the PCE to
evaporate. However, large quantities of PCE had remained in the liner of the
approximately 660 miles of VL/AC pipes in Massachusetts, and was leaching into
public drinking water supplies.

To assess how drinking
PCE-contaminated water in early life might have affected the mental health of
adults in subsequent years, Aschengrau and colleagues studied a total of 1,512
subjects born between 1969 and 1983, including 831 subjects with both prenatal
and early childhood PCE exposure, and 547 unexposed subjects. Questionnaires
were used to gather information on mental illnesses, demographic and medical
characteristics, other sources of solvent exposure, and residences from birth
until 1990. Water distribution system modeling software that incorporated a
leaching and transport algorithm was used to quantify PCE exposure originating
from VL/AC pipes.

The authors found elevated
risks of bipolar disorder and post-traumatic stress disorder that increased
further for the highest exposures in individuals with early-life exposure to
PCE. Conversely, exposed subjects were not at increased risk of developing
depression. 

Aschengrau emphasizes the importance of replicating these findings in other
studies before any firm conclusions can be drawn: “Because this is the first
study to examine the risk of bipolar disorder and post-traumatic stress disorder
following early life exposure to PCE, its results must be corroborated among
other similarly exposed populations.”

The same authors also
recently published a study in which
they found that risky behaviors, especially drug use, are more frequent among
adults with high PCE exposure levels during early life. Given that PCE remains
a common contaminant of drinking water supplies it is important that further
studies are performed to shed more light on the impact of early-life PCE
exposure on the health of vulnerable populations.