Mean Concentrations Of Pesticides Research Articles

Pesticides and Polychlorinated Biphenyls in Milk and Dairy Products in Croatia: A Health Risk Assessment.

The aim of this study was to evaluate contamination levels and the frequency of detection of organochlorine (OCPs) and organophosphate pesticides (OPPs), pyrethroids, carbamates and polychlorinated biphenyls (seven PCB congeners) in a total of 534 samples of cow's, sheep's and goat's milk and dairy products from Croatia. Concentrations above the limit of quantification (LOQ) were measured for fourteen OCPs, nine OPPs, six pyrethroids, one carbamate and PCBs with a total of 172 results, and no concentrations exceeded the maximal residue levels defined by the European Union. The mean concentrations of pesticides and the sum of seven PCBs were determined in the ranges 0.92-17.4 μg/kg and 1.38-2.74 μg/kg. Pesticides were quantified in 27% of samples, and seven PCBs were quantified in 5.23% of samples. Among the three pesticide groups, the highest numbers of quantified results were found for OCPs (12.1-20.8%). The highest frequencies of detection were found for the sum of 4,4'-dichlorodiphenyltrichloroethane and its isomers (DDTs), hexachlorobenzene and seven PCBs. The sum of seven PCBs was quantified within the range of 3.3-6.67% of samples per milk type and dairy products. Among the OPPs, the highest frequency of detection was found for chlorpyrifos in cow's milk. Based on the estimated daily intakes, chronic risk characterisation showed no risk for adults or ten-year-old children for the consumption of cow's milk and dairy products.

Ecological and Human Health Risk Assessment of Pesticide Residues in Fish and Sediments from Vea Irrigation Reservoir

The low yield of food production ascribed to harm caused by pests has led to the application of pesticides to food crops. Pesticide residues from the application on crops are mostly found in foods that can cause diseases for consumers of such products. A total of 37 pesticide residues consisting of 15 organochlorines (OC), 13 organophosphorus (OP) and 9 synthetic pyrethroids (SP) were determined. The QuEChERS method was exploited for extraction and clean-up. Gas Chromatograph was used for detection and quantification which was equipped with an electron capture detector and pulse flame photometric detector. The results showed that the mean concentrations of pesticides in fish ranged from 0.007 mg·kg-1 to 1.026 mg·kg-1 for OCs, 0.002 mg·kg-1 to 0.190 mg·kg-1 for OPs and 0.004 mg·kg-1 to 0.032 mg·kg-1 for SP. Sediments have mean concentrations ranged from 0.005 mg·kg-1 to 1.207 mg·kg-1 for OCs. OP ranges from 0.002 mg·kg-1 to 0.399 mg·kg-1 and 0.003 mg·kg-1 to 0.202 mg·kg-1 for synthetic pyrethroids. Maximum Residue Limits were exceeded in both fish and sediment samples except for malathion, fenitrothion, profenofos, gamma-chlordane, and deltamethrin. Exposure in children ranged from 4.60 × 10-6 mg·kg-1·d-1 to 2.36 × 10-3 mg·kg-1·d-1 and in adults it is from 1.97 × 10-6 mg·kg-1·d-1 to 1.01 × 10-3 mg·kg-1·d-1. Health risk estimation revealed a non-cancer risk potential of β-HCH in sediment and aldrin and p,p'-DDE in fish. Carcinogenic risk assessed for organochlorine pesticide residues indicates cancer benchmark concentrations greater than 10-4 to 10-6 threshold for acceptance.

Pesticide residues in soils planted with Panax notoginseng in south China, and their relationships in Panax notoginseng and soil.

In this study, 73 samples from soils planted with Panax notoginseng and six P. notoginseng samples were collected in Yunnan Province to investigate the residual levels of six pesticides and their relationships with P. notoginseng and soil. All six pesticides were detected in the soils planted with P. notoginseng located in three regions of Shilin, Kaiyuan, and Yanshan. The detection frequencies of the pesticides in the soils followed the order: quintozene (100%)>iprodione (96%)>procymidone (69%)>chlorothalonil (51%)>pyrimethanil (49%)>pyraclostrobin (29%). The median concentrations of iprodione, pyraclostrobin, pyrimethanil, quintozene, procymidone, and chlorothalonil were 46.40, 6.4, 3.1, 2.86, 2.69, and 0.24μg/kg, respectively. The mean concentrations of pesticides in the three regions followed the order: Kaiyuan>Shilin>Yanshan, except for iprodione. Furthermore, the concentrations of pesticide residues in soils in each region followed the order: soils never planted with P. notoginseng<soils previously planted with P. notoginseng<soils currently planted with P. notoginseng. The concentration of chlorothalonil in P. notoginseng followed the order: root>stem>leaf, whereas those of the other five pesticides followed the opposite order: root<stem<leaf. There were significant positive correlations between the mean concentrations of pesticides in P. notoginseng and those in the corresponding soils. These results indicate that the rational application of pesticides in P. notoginseng cultivation would be effective for reducing the accumulation of pesticides in P. notoginseng to protect people from the harmful effects of residual pesticides.

Organochlorine pesticide residues in European sardine, horse mackerel and Atlantic mackerel from Portugal

This paper reports the results for the surveillance of nine organochlorine pesticides (HCH isomers (α, β, e, γ), p,p′-DDD, p,p′-DDT, p,p′-DDE, p,p′-DDD, HCB and aldrin) in muscle of three fish species, European pilchard (Sardina pilchardus), Atlantic horse mackerel (Trachurus trachurus) and Atlantic mackerel (Scomber scombrus). Analytical methodology included n-hexane extraction, clean-up with 2% deactivated Florisil, and quantification with gas chromatography-electron capture detection (GC-ECD). The highest mean concentrations were found for p,p′-DDT in sardine and mackerel at levels of 30.1 and 109.9 µg kg−1, respectively, and for p,p′-DDD in horse mackerel at 51.9 µg kg−1. Three species had higher levels for Σ-DDT than Σ-HCH. The estimated daily intake of organochlorine pesticides in the three species showed that in sardine, the highest EDIs were found for aldrin, at 1.8 ng kg−1 bw day−1, which represents 1.8% of the acceptable daily intake (ADI), and for β-HCH, at 4.0 ng kg−1 bw day−1, representing 0.4% of ADI. Lowest values were found for Atlantic mackerel. Statistical analysis to determine the differences in mean concentrations of pesticides between species, and any correlation between groups of residues related with each one of the species, was undertaken.

Fate of pesticides in tropical soils of Brazil under field conditions.

The potential of pesticides for nonpoint ground water pollution depends on their dissipation and leaching behavior in soils. We investigated the fate of 10 pesticides in two tropical soils of contrasting texture in the Brazilian Cerrado region near Cuiabá during an 80-d period, employing topsoil dissipation studies, soil core analyses, and lysimeter experiments. Dissipation of pesticides was rapid, with field half-lives ranging from 0.8 to 20 d in Ustox and 0.6 to 11.8 d in Psamments soils. Soil core analyses showed progressive leaching of polar pesticides in Psamments, whereas in Ustox pesticides were rapidly transported to 40 cm soil depth regardless of their sorption properties, suggesting that leaching was caused by preferential flow. In lysimeter experiments (35 cm soil depth), cumulative leaching was generally low, with < or = 0.02% and < or = 0.19% of the applied amounts leached in Ustox and Psamments, respectively. In both soils, all pesticides but the pyrethroids were detected in percolate at 35 cm soil depth within the first 6 d after application. Cumulative efflux and mean concentrations of pesticides in percolate were dosely correlated with their Groundwater Ubiquity Score (GUS). The presence of alachlor (2-chloro-2', 6'-diethyl-N-methoxymethylacetanilide), atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine), metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], simazine [2-chloro-4,6-bis(ethylamino)-1,3,5-triazine], and trifluralin (2,6-dinitro-N,N-dipropyl-4-trifluoromethylaniline) throughout the soil profile and in percolate of wick lysimeters at 95 cm soil depth indicated that a nonpoint pollution of ground water resources in tropical Brazil cannot be ruled out for these substances.

Fate of Pesticides in Tropical Soils of Brazil under Field Conditions

The potential of pesticides for nonpoint ground water pollution depends on their dissipation and leaching behavior in soils. We investigated the fate of 10 pesticides in two tropical soils of contrasting texture in the Brazilian Cerrado region near Cuiabá during an 80-d period, employing topsoil dissipation studies, soil core analyses, and lysimeter experiments. Dissipation of pesticides was rapid, with field half-lives ranging from 0.8 to 20 d in Ustox and 0.6 to 11.8 d in Psamments soils. Soil core analyses showed progressive leaching of polar pesticides in Psamments, whereas in Ustox pesticides were rapidly transported to 40 cm soil depth regardless of their sorption properties, suggesting that leaching was caused by preferential flow. In lysimeter experiments (35 cm soil depth), cumulative leaching was generally low, with ≤0.02% and ≤0.19% of the applied amounts leached in Ustox and Psamments, respectively. In both soils, all pesticides but the pyrethroids were detected in percolate at 35 cm soil depth within the first 6 d after application. Cumulative efflux and mean concentrations of pesticides in percolate were closely correlated with their Groundwater Ubiquity Score (GUS). The presence of alachlor (2-chloro-2′,6′-diethyl-N-methoxymethylacetanilide), atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine), metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], simazine [2-chloro-4,6-bis(ethylamino)-1,3,5-triazine], and trifluralin (2,6-dinitro-N,N-dipropyl-4-trifluoromethylaniline) throughout the soil profile and in percolate of wick lysimeters at 95 cm soil depth indicated that a nonpoint pollution of ground water resources in tropical Brazil cannot be ruled out for these substances.

Tigris-Euphrates Delta: a major source of pesticides to the Shatt al-Arab River (Iraq).

Organochlorine pesticides were determined in the Tigris-Euphrates-Shatt al-Arab Delta by high resolution gas chromatography. Mean concentrations of pesticides in the dissolved form were (in ng/L) 98p,p'-DDE; 8o,p'-ODD; 28p,p'-DDD; 16p,p'-DDT; 30 aldrin; 66 dieldrin; 57cis-chlordane; 15trans-chlordane and 10 heptachior. Particulatep,p'-DDE;p,p'-DDT; endrin;cis-chlordane and heptachior mean concentrations at this location were 76, 67, 154, 11, and 68 (Μg/kg, dry weight, respectively. Partitioning of dissolved pesticides was evident along the Shatt al-Arab River, which was reflected by significantly higher levels of particulate species down river. Residues ofp,p'-DDE;p,p'-DDD;p,p'-DDT; endrin and dieldrin were confirmed in sediments from this river (mean concentrations were 19, 4, 3, 7, and 14 Μg/kg, dry weight, respectively); however, DDD was confined to the anoxic sub-surface layers only. Absorbing pesticides from both water and suspended particulate matter, Shatt al-Arab mussels had mean residue concentrations as follows (Μg/kg, wet weight) 43p,p'-DDD; 12o,p'-DDD; 15p,p'-DUT; 166 endrin; 26 aldrin; 24 dieldrin; 6cis-chlordane and 5 trans-chlordane. The Euphrates River was the major source of pesticides in the dissolved form, while the Tigris River contributed pesticides mainly in the particulate form to the Shatt al-Arab River. The sediment of this river was the largest reservoir of organochlorine pesticides, where more than 80% of the studied contaminants reside.