Environmental Engineering Reference
In-Depth Information
countries as well, indicating global occurrence in marinas and harbors, and
waters with high shipping activities. Furthermore, TPT and its degradation
products DPT and MTP have been detected, originating from older antifoul-
ing paints [14]. Phenyltins have still been detected in the last few years in
sediments [54] (Figs. 3 and 4), biota [15, 81, 82] and in the deep-sea [16, 17].
Numerous monitoring studies indicate that TBT pollution originating
fromantifoulingpaintsisglobalandhasspreadintodevelopingcoun-
tries [83-91], and even to the Arctic [92] and Antarctic [93]. Recent moni-
toring data using biota demonstrate global pollution of coastal areas. Studies
mainly from Asian developing countries indicate a similar contamination pat-
tern of harbors and estuaries as in developed countries. Moreover, monitor-
ing data 7-10 years after regulations of TBT-antifouling paints demonstrate
that the decrease is not substantial, as contamination remains at similar lev-
els [94]. Only a few reports indicate a decrease in marine systems [95].
Besides leaching from antifouling paints, TBT reaches the aquatic system
via wastewater due to its biocidal and fungicidal use. Leaching from PVC
products leads to inputs of butyl- and methyltins into the aquatic environ-
ment via wastewater [30]. Municipal wastewater and sewage sludge are con-
taminated with organotins at low ng L
-1
and 0.1-2.2 mg kg
-1
(dry wt) [50],
respectively. Moreover dialkylated organotins and even TBT are also released
from containers into foodstuff and beverages [96] and ultimately to aquatic
systems.
4.1
Seawater and Sediments
TBT contamination of marine and freshwater environments is well docu-
mented. In this review, emphasis will be placed on recent data after the re-
gulation of TBT-containing antifouling paints in recreational boats, whereas
data prior to antifouling paint regulations are compiled in [3, 4, 11, 34]. Re-
cent reports document the global occurrence of organotins [74, 75, 87, 90].
Any decrease was slow or absent after legislation limiting TBT usage on plea-
sure boats. In France, the decline was found to level off after 10 years and
relatively high TBT levels were detected even outside harbors [17]. In the
UK 10-78 ng L
-1
were detected in marinas and harbors in 1998, 8 years after
legislation [97]. Similarly, coastal levels remained at 2-160 ng L
-1
in 1999
in Japan [94]. The historic development of contamination using biota [98]
documented no noticeable decrease. Elevated TBT levels in marine systems
were, and still are, associated with increased pleasure and commercial boat
activities, or vessel repair facilities and dry docks, but also with the use of an-
tifouling paints on fish nets and cages in aquaculture [94]. Elevated levels of
organotins were reported in estuaries including the Japanese coast with TBT
levels up to 160 ng L
-1
[94] or in ferry ports with 200 ng L
-1
[99], but also in
open waters [74], and areas with high shipping activities [83], and the deep
