Bis(isopropyl)naphthalene

Endpoint summary

Additional information

Monitoring data

In Japan, DIPN was detected in environmental samples from two locations. In sea mud from the mouth of a river (Osaka Bay), 0.019 to 0.16 ppm (n = 5) of DIPN were analysed and in sea fish (Yokkaichi Bay), levels of ca. 0.003 ppm (n = 7) were found (Sumino 1977). In the years 2009 and 2010, samplig was continued in the Southern Hyogo prefecture, which embraced 41 sampling points in the Osaka bay and the Seto Inland Sea (Suzuki et al. 2012).

 

Close to a paper recycling plant, DIPN concentrations in river sediment were found to be 0.3 - 23.0 µg/g (Sato 1980). At the waste water discharge of another plant, 2200 µg/g were analysed but 100 m downstream, only concentrations of 8.5 µg/g were detected (Haga et al.1984).

 

Environmental monitoring data in surface water, sediment and fish of the years 1975, 1977, 1980 and 2005/2006/2007 demonstrate that

        -      DIPN was detectable in 10 out of 400 water samples with a maximum of 0.0044 µg/L.

-      DIPN was positive in 35 out of 358 sediment samples (10 %) with a maximum (2005) of 7500 µg/kg dry weight

-      DIPN was positive in 41 out of 349 fish samples (12 %) with a maximum (1975) of 48 µg/kg wet weight.

  [Environment Agency, Japan, 1998;Chemical Risk Information Platform(CHRIP)].

In 2009 and 2010 (Suzuki et al. 2012), the monitoring programme continued in sediment of the sea coast and river estuaries as well as seawater of the same area:

- Seawater: <1.9 - 9.8 ng/L DIPN was found.

- Sediment: <1.1 - 100 µg/kg dw (30 points in 2009), the highest solitary contamination of 4400 µg/kg dw was detected in a river sediment of a river without a relevant industrial source.

- Fish tissue (Japanese sea perches): 1.2 - 3.4 µg/kg ww (five samples). There was no difference in the levels of DIPN in males and females; however, the isomers 1,3- and 1,4 -DIPN were more pronounced in female perch.