Pesticide Residues in Fish - Pesticides: Evaluation of Environmental Pollution - page 378

were likely the DDTs sources to seawater-farmed fish. Occurrence of organochlorine pes-
ticides in fish tissues was examined to assess input sources and modes of bioaccumulation
in the Pearl River Delta, China (Guo et al. 2008).
Fishery products are very popular in the Taiwanese cuisine. The major raw materials
include fish, crab, shrimp, bivalve, and cephalopod. Pesticide residues in fishery prod-
ucts should be of great concern to consumers. The residue data will enable us to estimate
pesticide dietary intakes in citizens and to compare them with acceptable daily intakes
(ADIs) of the Food and Agricultural Organization (FAO) as well as with the World Health
Organization (WHO), so as to assess potential health hazards.
A study was carried out to find the concentration levels of pesticide residues in edible
parts of consumed fishery products in the market. A total of 920 samples of fishery products
were analyzed for pesticide residues from the years 2001 to 2003. Overall, 65.40% of fish,
93.55% of shellfish, 84.92% of crustacean, and 98.33% of cephalopod samples contained
no detectable residues. There are no detectable residues of carbamate and pyrethroid
pesticide in surveyed samples. OCP residues are detected in 144 (34.60%) fish, 4 (6.45%)
shellfish, and 28 (15.7%) crustacean samples. Organophosphate (OP) pesticide residues
are detected in 69 (11.37%) fish, 2 (1.05%) crustacean, and 1 (1.67%) cephalopod samples.
Fish had higher detection rates of OC and OP pesticides. These pesticides, however, were
not detected in cephalopod or shellfish. Multipesticide residues were detected only in 22
(3.62%) fish samples. This result is similar to the no detectable rate of FDA domestic sea-
food in 1998, 1999, and 2000 separately (21.50% in 1998, 28.90% in 1999, 24.60% in 2000) but
is higher than that in 2001 (18.4%) (FDA 1999, 2000, 2002, 2003). As for the 91 pesticides,
DDT, dieldrin, chlorpyrifos, fenitrothion, fenthion, and prothion have been detected from
fishery products. The predominant residues are DDTs (including p,p′-DDD, p,p′-DDE, and
p,p′-DDT). DDT and dieldrin were banned in the 1970s in Taiwan for their long persistence
in environment. There are no studies on OC pesticide incidence in products of fish farms
in Taiwan so far. Chlorpyrifos, following DDTs, is one of the main detectable residues in
fishery products, especially in the nationwide supermarkets (in 30 samples, 10.07%) and
regional supermarkets (in 29 samples, 14.08 %). The next detectable residue is fenitrothion.
Chlorpyrifos and fenitrothion are widely used not only in agriculture but also in sanitation
in Taiwan. In fishery product processing, both supermarkets have the highest standards
on hygienic conditions. However, in the national supermarkets (nationwide chain store),
the service of processing is at sight, whereas in the regional supermarket, the same service
is through the central kitchen.
Chlorpyrifos is one of the most widely used active ingredients for pest control in the
world. Many studies have been conducted in examining critical aspects of chlorpyrifos
products as they relate to health and safety (Dishburger et al. 1997; Johnson et al. 1998;
Clegg and Gemert 1999). There are no reports directly pertaining to the contamination
of sanitary chemicals on fishery products. In both kinds of supermarkets, higher mul-
tipesticide residues have been detected: in 9 samples of national supermarket (3.02%) and
12 samples of regional supermarket (5.83%).
The Indian Ocean coastal environment of Kenya contains critical terrestrial and
aquatic habitats, which comprise unique ecosystems and support a rich biological diver-
sity and valuable assortment of natural resources, which may be adversely affected by
pesticide residues transported from inland waterways into coastal waters via rivers
and estuaries through flooding, deposition, and rainfall (UNEP 1998). Marine fish are
regarded as good bioindicator species for evaluating pesticide exposure toxicity levels
in marine environments, and their susceptibility is depicted by reduction in species
richness (Matin 2002).