Distribution of Persistent Organic Pollutants and Mercury in Freshwater Ecosystems Under Changing Climate Conditions - Climate Change Impacts on Freshwater Ecosystems - page 183

Table 8.2 Concentrations of PCBs and DDTs in waters from remote sites (mean ±
standard deviation). (From Vilanova et al . 2001a; Fernandez et al . 2005.)

PCBs (pg l −1 ) DDTs (pg l −1 )

Location Total Particulate Dissolved % in SPM Total

Ladove Lake Sept.
2000

64 ± 30 33 ± 8 31 ± 31 59 ± 19 12 ± 3

Lake Redon Nov.
2000

79 53 26 67 9.6

Lake Redon May
2000

56 ± 11 28 ± 8 29 ± 8 7.1 ± 2.9

Lake Redon
(1996-8)

62 ± 44 16 ± 28

Lake Gossenkölle
(1996-7)

110 ± 64 14 ± 6.3

Øvre Neådalsvatn
(1998)

26 ± 5.4 0.59 ± 0.40

Amituk Lake
(1994, Arctic)

372 27

Arctic Ocean
(1990, 1992-4)

1.0 ± 0.30*

Easthwaite Water
Lake (1996-7)

680 ± 190 †

Lakes in southern
Sweden (1997)

8-144 ‡

* Only dissolved phase.
† Sum of 61 PCBs.
‡ Sum of 49 PCBs.

rather, it is general to the entire planet. These compounds pose a new toxic
threat. Humans are exposed to small doses starting in the womb and continuing
throughout life. The consequences of the combined long-term effects of such
exposure must be evaluated. Health problems due to exposure in the developmental
phase may not appear until a much later age. For example, links between oncogene
mutation and higher blood concentrations of some of these compounds in
patients with colon cancer (Howsam et al . 2004) or exocrine pancreatic cancer
have been observed (Porta et al . 1999). These compounds may even cause
problems in the earliest stages of life. Indeed, decreases in cognitive ability have
been correlated with intrauterine exposure to DDT (Ribas-Fito et al . 2006).
Wheezing at age 6 has been reported in association with prenatal exposure to
DDE (Sunyer et al . 2005, 2006) and increases in attention deficit and hyperactivity
disorders in young children have been attributed to high exposure to HCB during
the neonatal period (Ribas-Fito et al . 2007). An increase in global temperature
will lead to greater volatilization and, consequently, to higher concentrations of
these compounds in the atmosphere and in aquatic systems and ultimately in the
human body.