Pesticide contamination of Jamaican environment. II. Insecticide residues in the rivers and shrimps of Rio Cobre basin, 1982-1996.

Abstract

Only organochlorine (OC) residues were monitored by gas chromatographyin water, sediment and shrimp samples collected everymonth between July 1982 and August 1983 from therivers of Rio Cobre basin. In samples collected everyfour months during 1989–1990, and seven times duringJuly 1995–March 1996, OC and OP (organophosphates)residues were monitored. Carbamate and pyrethroidresidues were not monitored. The detection ofresidues in 1982–1983 was 54 to 100% in water andsediment, and 83 to 100% in shrimp samples fromvarious sampling stations in the four rivers. In otheryears, it ranged from about 40 to 100% in the threetypes of samples.In 1982–1983, DDE and dieldrin residues were found tobe much higher than those of lindane and α- andβ-endosulfan in Black River, Rio Pedro, ThomasRiver and Rio Cobre in the watershed. The ranges ofmeans of each residue in water (μg L-1), sediment(ng g-1) and shrimp (ng g-1) samples, respectively, were:DDE, 0.059–102.0, 3.44–13.97, 0.344–14.57;dieldrin, 0.026–173.6, 1.21–2.75, 0.427–5.59;α-endosulfan, bdl, 1.75–4.00, bdl;β-endosulfan, bdl (below detectable limits), 2.51–9.48, bdl;and lindane, (bdl), 0.110–0.319, 2.90.In 1989–1990 and 1995–1996, residues of six OCs and two OPs were detected quite regularly. DDE, dieldrinand Chlorpyrifos residues were much higher than thoseof the other insecticides. The range of their meansin water (μg L-1), sediment and shrimp (ng g-1),respectively, were: DDE, 1.66–19.76, 0.941–5.84,1.11–8.32; dieldrin, 0.077–7.22, 0.425–3.31,0.385–1.59; α-endosulfan, 0.034–1.25, 0.021–1.22, 0.032–3.62; β-endosulfan, 0.665–1.23,0.008–3.60, 0.005–3.97; endosulfan sulphate, 0.959–1.34, 0.035–3.08, 0.012–1.80; lindane, bdl,0.005–0.82, 1.19–1.56; chlorpyrifos, 0.702–4.06,0.005–1.51, 0.156–7.04; and diazinon, bdl, 0–0.150, 0.001–0.006. At the mouth of the river, whereit discharges into the sea, the levels of almost allthe residues were higher than upstream.