Civil Engineering Reference
In-Depth Information
and upholstery cleaners, sealants and silicones (US EPA
2001
). Polluted drinking
water may be a source of indoor PCE, while taking a shower or washing dishes.
Dry-cleaned clothes may also emit PCE in dwellings (WHO
2010
).
Emissions of PCE have historically been related with its use as a solvent in dry
cleaning (Doherty
2000b
). Dry-cleaning machines recover the main part of PCE
employed, but atmospheric emissions result from evaporation and leakages during
the process (Hellweg et al.
2005
). A study conducted in 196 dwellings has revealed
that indoor concentrations of PCE increase with the proximity to dry-cleaning
facilities, the use of consumer products containing PCE, aeration and ventilation,
and the age of the building (Roda et al.
2013
). Nowadays, main uses of PCE in
Europe are as raw material to produce fluorinated hydrocarbons, fluorinated
polymers, other fluorinated derivatives, and TCE. PCE is also industrially used for
textile treatment, cleaning of metal surfaces and for catalyst regeneration in petrol
industry (European Chlorinated Solvent Association
2012
).
Figure
10
shows PCE indoor and outdoor concentrations obtained from the same
studies as for TCE. Data suggest that generally indoor concentrations are greater
than outdoors. Standard errors were of the same order of magnitude except in the
MNCPES study, which reported high indoor standard error of the mean, due to
the variability of PCE concentration indoors—the 95 % confidence interval on the
mean ranges from 0.4 to 6.6 lg/m
3
—(Clayton et al.
1999
). Significant differences
between indoor residential and outdoor concentrations of PCE were found in some
studies (Clayton et al.
1999
; Adgate et al.
2004
; Weisel et al.
2005
), indicating
the existence of indoor sources at homes. Apart from the studies on Fig.
9
, the
EXPOLIS study reported that most PCE data were below the detection limits: in
Helsinki 91 % of indoor data and 99 % of outdoor values (Edwards et al.
2001
) and,
7.5
5.0
2.5
0.0
Cities >100.000
inh., USA [1]
EPA Region 5,
USA [2]
Minnesota,
USA [3]
Three urban
centers, USA [4]
Bilbao,
Spain [5]
Workplace (building) indoor
Residential indoor
Outdoor
Fig. 10 Selected indoor and outdoor average concentrations of PCE from various studies: (1)
BASE study (US EPA
2013a
), (2) NHEXAS (Clayton et al.
1999
), (3) MNCPES (Adgate et al.
2004
), (4) RIOPA (Weisel et al.
2005
), (5) de Blas et al. (
2012
). Bars indicate standard errors
