19 / 2023-12-18 00:43:47

Temporal Variation Analysis of Organochlorine Pesticides in Water and Sediments in Tucutunemo River Basin, Venezuela

Temporal variation,Organochlorine Pesticides,OCPs dissolved in water,OCPs sorbed on sediments,tropical rivers

In this paper, it is analyzed as a novelty, temporal variation of organochlorine pesticides (OCPs) in water and sediments in Tucutunemo river basin, Venezuela, influenced by agricultural uses during period 2013-2016.  Within the applied method, water and sediment samples were collected every six months, in dry (April) and rainy (October) seasons, from 2013 to 2016. Water and sediment sampling was repeated every three days, so that in each season, 9 simple samples were collected, corresponding to 3 samples per station with 3 repetitions in each of them. Water samples were manually collected in amber glass jars, of one liter in capacity, with plastic lids, previously washed and sterilized, in the center line of the river’s cross section, in the middle of the channel depth. Sediment samples were collected as a thin superficial sheet from a layer from 0 to 10 cm thick in riverbed and riverbanks, with an approximate weight of 500 g and were placed in clean plastic bags of 2 kg capacity. Analytic determination of OCPs was carried out in Environmental Quality Laboratory of the Ministry of Ecosocialism, Housing, and Habitat. A total of 72 water and sediment samples were collected in three years. A review was carried out from the end of the 20th century to the present, regarding characterization of OCPs in water and sediments, finding: in river water, concentrations of DDTs were similar by comparing with nine studies while the concentrations of DRINs were lower in ten times than those observed in one of a total of nine studies. It is recommended to increase monitoring of DRINs in water of rivers. In sediments, concentrations of DDTs were similar by comparing with 22 studies of a total of 31 studies while concentrations of DRINs were higher in 100 times than those observed in ten of 31 studies. It is recommended to increase the monitoring of DRINs in sediments of rivers. Average OCPs in water and sediments varied as follows: p.p'-DDT (0.001 – 0.022 µg.L^-1), (0.1 – 8.24 µg.kg^-1), o.p'-DDT (0.001-0.021 µg.L^-1), (0.51 – 5.76 µg.kg^-1), p.p'-DDD (0.001-0.01 µg.L^-1), (0.14 – 1.96 µg kg^-1), p.p'-DDE (0.001-0.027 µg.L^-1), (0.52 – 7.32 µg.kg^-1),  o.p'-DDE (0.001-0.041 µg.L^-1), (0.2 – 5.52 µg.kg^-1),   Aldrin (0.004-0.053 µg.L^-1), (0.23 – 8.22 µg.kg^-1),    Dieldrin (0.001-0.032 µg.L^-1), (1.13 – 6.82 µg.kg^-1), and Endrin (0.001-0.008 µg.L^-1), (1.16 – 7.60 µg.kg^-1). Management of organochlorine pesticides by activity in agricultural field is being controlled causing the occurrence of concentrations that would allow potential use of waters for human.