14
K. Kuroda and J. Kobayashi
1.3.3 Japan
In Japan, the occurrence of PPCPs in groundwater has been investigated in central
Tokyo (Kuroda et al. 2012; Nakada et al. 2008). In these studies, crotamiton and carbamazepine were the most frequently detected PPCPs, followed by propyphenazone,
DEET, and caffeine. In the city-wide survey of 50 wells, the PPCP detection frequency was high in unconfined aquifers (<30 mbgl, 66% detection frequency) and
spring waters (100%), but even confined aquifers (30–500 mbgl) showed a 44% PPCP
detection frequency (Kuroda et al. 2012). The source of PPCPs in Tokyo’s groundwater was inferred to be leakage of sewage from sewer pipes. This groundwater pollution
by sewage was also considered to be the source of other contaminants in Tokyo’s
groundwater, including chlorate, perchlorate (Kosaka et al. 2013), perfluoroalkyl
acids (PFAAs; Kuroda et al. 2014; Murakami et al. 2009), N-nitrosodimethylamine
(NDMA; Van Huy et al. 2011), nitrate (Kuroda and Fukushi 2008; Kuroda et al.
2007), and bacteria (Kuroda et al. 2008; Kuroda et al. 2012). PPCPs have also been
detected in river waters in Japan (Kobahashi and Horiuchi 2007; Nakada et al. 2008).
Although not the case in Tokyo, the infiltration of river waters was considered to be
the source of groundwater PPCPs in areas such as basins with highly permeable
grounds (Kobahashi and Horiuchi 2007).
Ten years after a comprehensive survey of PPCPs in Tokyo’s groundwater in 2007
(Kuroda et al. 2012), the authors conducted a sampling campaign of 12 groundwaters and springs in Tokyo and analyzed 17 PPCPs, in 2017 and 2018. The results
(Table 1.2) showed that all 12 samples were positive for more than four PPCPs.
All 17 PPCPs except for triclosan were detected, and crotamiton (12/12, 100%) and
carbamazepine (10/12, 83%) were again the most frequently detected, followed by
sulfamethoxazole, sulfamonomethoxine, ampicillin, ibuprofen (7/12, 58%), caffeine,
and bezafibrate (6/12, 50%). Large concentrations of ibuprofen (1006 ng/L), caffeine
(86.7 ng/L), and bezafibrate (78.7 ng/L) were detected. The maximum concentration
of ibuprofen was comparable to sewage influents in the region (Nakada et al. 2006).
In this 2017–2018 survey, we revisited seven groundwater sites and two springs
that had been examined in the 2007 survey (Kuroda et al. 2012) and compared the
concentrations of crotamiton and carbamazepine (Fig. 1.1). The occurrence of PPCPs
in the two surveys was somewhat similar in the case of crotamiton and carbamazepine,
but the 2017–2018 survey tended to show more frequent detection of PPCPs, partly
because the limit of detection was lower in the 2017–2018 survey (0.38–1.61 ng/L)
than in the 2007 survey (0.82–21 ng/L). In contrast, there was a clear difference in the
occurrence of caffeine, which was detected in four locations in the 2017–2018 survey
(with concentrations up to 86.7 ng/L) and in none of the nine locations in the 2007
survey. As caffeine is somewhat labile to biodegradation, the detection of caffeine
is considered to indicate recent (or ‘fresh’) contamination by sewage (Buerge et al.
2003; Nakada et al. 2008). In the 2017–2018 survey, the groundwater samples were
mostly taken from unconfined aquifers (<30 mbgl), and the widespread detection
of PPCPs, including caffeine, suggests that the shallow groundwater and springs in
K. Kuroda and J. Kobayashi
1.3.3 Japan
In Japan, the occurrence of PPCPs in groundwater has been investigated in central
Tokyo (Kuroda et al. 2012; Nakada et al. 2008). In these studies, crotamiton and carbamazepine were the most frequently detected PPCPs, followed by propyphenazone,
DEET, and caffeine. In the city-wide survey of 50 wells, the PPCP detection frequency was high in unconfined aquifers (<30 mbgl, 66% detection frequency) and
spring waters (100%), but even confined aquifers (30–500 mbgl) showed a 44% PPCP
detection frequency (Kuroda et al. 2012). The source of PPCPs in Tokyo’s groundwater was inferred to be leakage of sewage from sewer pipes. This groundwater pollution
by sewage was also considered to be the source of other contaminants in Tokyo’s
groundwater, including chlorate, perchlorate (Kosaka et al. 2013), perfluoroalkyl
acids (PFAAs; Kuroda et al. 2014; Murakami et al. 2009), N-nitrosodimethylamine
(NDMA; Van Huy et al. 2011), nitrate (Kuroda and Fukushi 2008; Kuroda et al.
2007), and bacteria (Kuroda et al. 2008; Kuroda et al. 2012). PPCPs have also been
detected in river waters in Japan (Kobahashi and Horiuchi 2007; Nakada et al. 2008).
Although not the case in Tokyo, the infiltration of river waters was considered to be
the source of groundwater PPCPs in areas such as basins with highly permeable
grounds (Kobahashi and Horiuchi 2007).
Ten years after a comprehensive survey of PPCPs in Tokyo’s groundwater in 2007
(Kuroda et al. 2012), the authors conducted a sampling campaign of 12 groundwaters and springs in Tokyo and analyzed 17 PPCPs, in 2017 and 2018. The results
(Table 1.2) showed that all 12 samples were positive for more than four PPCPs.
All 17 PPCPs except for triclosan were detected, and crotamiton (12/12, 100%) and
carbamazepine (10/12, 83%) were again the most frequently detected, followed by
sulfamethoxazole, sulfamonomethoxine, ampicillin, ibuprofen (7/12, 58%), caffeine,
and bezafibrate (6/12, 50%). Large concentrations of ibuprofen (1006 ng/L), caffeine
(86.7 ng/L), and bezafibrate (78.7 ng/L) were detected. The maximum concentration
of ibuprofen was comparable to sewage influents in the region (Nakada et al. 2006).
In this 2017–2018 survey, we revisited seven groundwater sites and two springs
that had been examined in the 2007 survey (Kuroda et al. 2012) and compared the
concentrations of crotamiton and carbamazepine (Fig. 1.1). The occurrence of PPCPs
in the two surveys was somewhat similar in the case of crotamiton and carbamazepine,
but the 2017–2018 survey tended to show more frequent detection of PPCPs, partly
because the limit of detection was lower in the 2017–2018 survey (0.38–1.61 ng/L)
than in the 2007 survey (0.82–21 ng/L). In contrast, there was a clear difference in the
occurrence of caffeine, which was detected in four locations in the 2017–2018 survey
(with concentrations up to 86.7 ng/L) and in none of the nine locations in the 2007
survey. As caffeine is somewhat labile to biodegradation, the detection of caffeine
is considered to indicate recent (or ‘fresh’) contamination by sewage (Buerge et al.
2003; Nakada et al. 2008). In the 2017–2018 survey, the groundwater samples were
mostly taken from unconfined aquifers (<30 mbgl), and the widespread detection
of PPCPs, including caffeine, suggests that the shallow groundwater and springs in