Assessing malathion residue impact on poultry health, human safety, and production performance.

Over the past decade, food safety has become a major concern due to the intensive use of pesticides. Pesticide contamination has been observed in poultry products when seeds are coated with pesticides or when stored products are exposed to pesticides in warehouses. In this experiment, the residue levels of malathion transferred from corn grain to the different parts of the chicken product, its transfer factors (TFs) and the human dietary risk for consumers were evaluated. Growth performance and carcass parameters of the chicken samples were also determined after different doses of malathion exposure. Malathion residues from different parts of chicken meat (breast, thigh, wing, liver and skin) were extracted by the QuEChERS method and analyzed by liquid chromatography-mass spectrophotometry (LC-MS/MS). A deterministic approach was used to calculate the acute and chronic risk assessment. Body weight, feed conversion ratio and feed intake decreased with increasing malathion dose. In addition to reduced feed intake, cold carcass and liver weights of the chicks were also decreased. The highest residues were found in the skin of the chicken followed by the breast, thigh, wing and liver. The TFs of malathion varied between 0.00 and 0.05 according to the different doses applied (4 mg/kg, 8 mg/kg, 16 mg/kg, 32 mg/kg). The chronic exposure assessment (HQ) showed that consumers of all ages and genders consumed 0.008-0.604% of the acceptable daily intake (0.3 mg/kg body weight (bw)/day) of malathion from chicken products. The acute intake assessment (aHQ) of consumers ranged from 0.00015 to 0.0135% of the acute reference dose (0.3 mg/kg bw). In conclusion the results suggest that the risk associated with the malathion residues in chicken meat was found to be low but the residue levels in meat should not be ignored.

Removal of pesticide residues from apple and tomato cuticle.

Pesticide residues are always an unsolved problem in the world despite all kinds of prevention measures. The present research work is based on a scientific hypothesis, i.e., "The removal of average pesticide residue is inversely proportional to the thickness of cuticle." The effects of boron-containing products and plant-based surfactants were tested for the removal of five pesticides (lambda-cyhalothrin, chlorpyrifos, diflubenzuron, metaflumizone, acetamiprid) on tomatoes and apples. Boron-containing products were able to remove the pesticide residues on average between 58.0 and 72.6% in tomatoes and 33.2-58.8% in an apple. While plant-based surfactants removed residues on average between 58.5 and 66.6% in tomatoes and 41.0-53.2% in an apple. The highest removal rate was 72% with etidot at 1%. The solution of 1% C8-C10 provided 66.6% average removal for tomatoes. Less removal was achieved in apples. For an apple, Log Kow and molecular mass (independent variables) were significant with p < 0.01, and the coefficient of determination (R2) was > 0.87. However, the multiple linear regression analysis for ground colemanite was significant with R2 of 0.96. In tomatoes, neither Log Kow nor molecular mass as significant. The correlation was found between the physical and chemical properties of pesticides, but it is estimated that the thickness of the cuticle is effective in removing pesticides.

Evaluation of pesticide residues in fruits and vegetables from the Aegean region of Turkey and assessment of risk to consumers.

Pesticides may cause a potential risk to human health when applied in excess to control pests, diseases, and weeds in crop fields. In the current study, conducted in the Aegean region of Turkey from 2012 to 2016, a total of 3044 samples of 16 different commodities of fruits and vegetables were screened to identify pesticide residues and health risk to consumers posed by such residues was assessed. Results showed that 354 samples out of the total samples had higher maximum residue limit (MRL) values, while the MRL values were lower in 473 samples. In the study, residues of 64 different pesticides detected in 3044 samples in which 11.6% samples exceeded maximum residue limit (MRL) levels as compared with that of the approved MRL level by the Turkish authorities. Out of total samples, number of samples having high MRL level were as follows: 74 for chlorpyrifos (2.43%), 145 for azoxystrobin (3.8%), 112 for triadimenol (3.8%), 103 for carbendazim (3.4%), 98 for chlorpyrifos (3.2%), 94 for pyrimethanil (3.10%), 90 for cyprodinil (2.9%), 76 for fludioxonil (2.50%), 75 for indoxacarb (2.40%), 66 for imidacloprid (2.10%), and 60 for boscalid (1.90%). Residues of one, two, three, four, and even more than five pesticides were detected, respectively, in 16.1, 5.8, 2.8, 1, and 1.7% of the total test samples. The lowest estimated daily intake (EDI) values ranged from 3.57×10-3 to 8.98. The lower values of hazard quotient (HQ) were obtained in dried apricot, grape, and strawberry with the value of 0.01, although the HQ value in 32 out of 62 pesticides tested was found to be close to 0.

Pine needle and semi-permeable membrane device derived organochlorine compounds (OCPs) concentrations in air in Mersin Province to Taurus, Turkey.

Organochlorine pesticides (OCPs) were analyzed in three different ages (half-, 1.5-, 2.5-year-old) for needles and semi permeable membrane devices (SPMDs) at three deployment periods from sea level to 1881 meter above sea level. Individual HCHs concentrations ranged between 1.4 and 129 pg/g fw depending on the age and sampling season while 2.5-year-old needles showed higher HCHs levels compared to half and 1.5- year-old. Correlation between elevation and HCH concentration in SPMDs was found but not in needle samples. Concentrations of HCHs in SPMDs indicated clearly cold condensation effect on accumulation in winter period and increased with altitude. Concentrations of DDTs in half and 1.5-year-old needles were lower than 2.5-year-old needles. The highest total concentration of DDTs was detected in 1-year-period SPMD. Higher concentrations were found in 2.5-year-old needles for other OCPs. Seasonal and altitude-dependent changes were not observed for other OCPs in SMPDs. Total accumulation of OCPs in SPMDs were found higher than in needles. On the contrary, an increased accumulation rate was observed for HCHs in SPMD. In general, Total concentrations of DDTs and HCHs were similar to total of other OCPs in all altitudes when dominating endosulfan wasnot taken into account in the computation of total concentration of other OCPs.

Organophosphate esters in house dust: A comparative study between Canada, Turkey and Egypt.

Organophosphate esters (OPEs) are commonly used as flame retardants (FRs) and plasticizers. The usage of OPEs has increased recently due to the ban of several brominated flame retardants, but information on levels in the environment, including the indoor environment is still limited. We investigated the occurrence and distribution of 12 OPEs in urban house dust from Vancouver, Canada; Istanbul, Turkey; and Cairo, Egypt. The median ∑OPE concentration was 41.4 µg/g in the Vancouver samples while median levels in Istanbul and Cairo were significantly lower. The median composition profiles of OPEs in Vancouver and Cairo were dominated by tris (2-butoxyethyl) phosphate (TBOEP), accounting for 56 and 92% of total OPEs respectively while it showed a detection frequency of only 14% in Istanbul. Tris (2-chloropropyl) phosphate (TCPP) was the most abundant chlorinated OPE representing 20 and 36% of the total OPEs in Vancouver and Istanbul respectively, but was below the detection limit in the Cairo dust samples. Consistent with other studies, ΣOPE concentrations were ~1 to 2 orders of magnitude higher than PBDEs and currently used flame retardants in the same dust samples. The mean estimated daily intakes (EDI) of ΣOPE from dust were 115, 38 and 9 ng/kg/bw/day in Vancouver, Cairo and Istanbul respectively for toddlers where adults were ~10 times lower. The total toddler OPE intake ranged from 115 to 2900, 38 to 845 and from 9 to 240 ng/kg bw/day across the three cities. TBOEP had the largest contribution to the EDI in both toddler and adults, where toddler TBOEP exposures via dust represented 4% to 80%, 2% to 44% and 0.1% to 6% of the Reference Doses (RfD) in the mean and high intake scenarios for toddlers in Vancouver, Cairo and Istanbul respectively.

Polycyclic aromatic hydrocarbons (PAHs) determined by pine needles and semipermeable membrane devices along an altitude profile in Taurus Mountains, Turkey.

Polycyclic aromatic hydrocarbons (PAHs) were analyzed at different altitudes of Taurus Mountains in semipermeable membrane devices (SPMD) and in half-, one-and-a-half-, and two-and-a-half-year-old pine needles. SPMDs were deployed for three different exposure periods: March to September (Summer), September to March (Winter), and March to March (whole year) at eight sites where needle samples were collected. The values of PAHs in needles were between 4.4 to 6066 pg g/fw in half-year-old, 7.2 to 111,115 pg g/fw in 1.5-year-old, and 9.7 to 85,335 pg g/fw in 2.5-year-old needles. Mass of PAHs collected by SPMDs varied from

Olive tree, Olea europaea L., leaves as a bioindicator of atmospheric PCB contamination.

Olive tree leaf samples were collected to investigate their possible use for biomonitoring of lipophilic toxic substances. The samples were analyzed for 28 polychlorinated biphenyls (PCB) congeners. Twelve congeners were detected in the samples. PCB-60, 77, 81, 89, 105, 114, and 153 were the most frequently detected congeners ranging from 32 % for PCB-52 to 97 % for PCB-81. Σ12PCBs concentration varied from below detection limit to 248 ng/g wet weight in the sampling area, while the mean congener concentrations ranged from 0.06 ng/g (PCB-128 + 167) to 64.2 ng/g wet weight (PCB-60). Constructed concentration maps showed that olive tree leaves can be employed for the estimation of spatial distrubution of these congeners.

Evaluation of organochlorine pesticides in breast milk samples in Turkey applying features of the partial order technique.

Exposure data to organochlorine pesticides (OCPs) of mothers' breast milk samples were measured in different locations in the Taurus Mountains/Turkey. Villages at five altitudes were looked upon. The data analysis method applied is the Hasse diagram technique, based on Discrete Mathematics. For each of the five regions, one Hasse diagram was calculated and showed the same maximal object, namely, p-p'-Dichlorodiphenyldichloroethane (DDE). In a further data investigation step, we performed the similarity analyses of the locations in order to quantify the similarities and incomparabilities. It was revealed that no correlation exists between most altitudes and the pattern of contamination of breast milk samples. The two lowest situated areas, Sahil at sea level and Ciftlikköy at 121 m above sea level were similar. We reduced the datasets by applying the interval analysis followed by similarity analyses. We observed that endrin (END1), mirex (MIRE), and pentachlorobenzene (PECB) reduce most severely the similarity.

The source of DDT and its metabolites contamination in Turkish agricultural soils.

The concentration and impact of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)-ethane (DDT) and its metabolites (DDE: 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene) on the environment was expected to decrease after its ban in the mid-1980s. Unfortunately, DDT contamination via its presence as an impurity in dicofol (2,2,2-trichloro-1,1-bis(4-chlorophenyl)ethanol) has led to a new source of contamination. This is particularly true especially in cotton production in Söke Plain, Turkey, where difocol-based pesticides are being used. The aim of this research was to investigate the extent and source of DDT contamination in cotton soils. Söke Plain soil samples were collected from 0-30, 30-60, and 60-90-cm depth and analyzed by GC/MS/MS. o,p'-DDT and p, p'-DDE were detected at 16.2 % and 17.6 % of the sites in the 0-30-cm depth of soils. In the 30-60 cm, p, p'-DDT (14.9 %), o, p'-DDE (8.1 %) and p, p'-DDE (2.7 %) were found in soil samples, and p, p'-DDT was the most prevalent with 9.5 % of the sampling sites. The dominant source of DDT particularly in the 60-90-cm depth was due to historic use of DDT. The presence of p, p'-DDE, o, p'-DDE and p,p'-DDT in the topsoil was attributed to recent dicofol applications.

Analysis of human milk to assess exposure to PAHs, PCBs and organochlorine pesticides in the vicinity Mediterranean city Mersin, Turkey.

Assessment of human exposure to environmental persistent organic pollutants such as organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and polycyclic aromatic hydrocarbons (PAHs) based on the levels in human breast milk provides a reasonable tool not only to assess the contaminant burden in mothers but also to assess potential exposure of breast-fed neonates. There are limited data on levels of PCBs and OCPs in humans but no previous reports from Turkey on chemically determined levels PAHs in human milk. The aim of this study was to report the levels and accumulation profiles of OCPs, PCBs and PAHs in 47 breast milk samples obtained from a Mediterranean city, Mersin. High resolution analyses were performed by a gas chromatography coupled with mass spectrometer (GC-MS). Dichlorodiphenyldichloroethane (4.4'-DDE) was the dominant pollutant. Beta-hexachlorocyclohexane (ß-HCH), dichlorodiphenyltrichloroethane (4.4'-DDT), dieldrin, hexachlorobenzene, oxy-chlordane, cis-heptachlorepoxide were the other main OCPs detected. Mean levels of ΣPCB congeners and WHO(PCB)-TEQ were 9.94 and 0.001 ng/g lipid, respectively. PCB 153 showed the highest concentration (3.37 ng/g lipid), followed by PCB 138 and 180. For the dioxin-like PCBs, PCB 118 was the dominant (0.97 ng/g lipid). Naphthalene, phenanthrene, pyrene and fluoranthene were the major PAHs among the 16 PAHs detected. The estimated daily intakes of DDTs, PCBs, HCHs and HCB were not exceeded the tolerable daily intake (TDI) proposed by the Health Canada Guideline. These results indicate that the neonates of Mersin city are exposed to persistent organic pollutants analyzed in this study. However, neonates born in Mersin province are less exposed than the ones born in other regions, considering OCP and PCB levels in breast milk.

The occurrence and environmental effect of persistent organic pollutants (POPs) in Taurus Mountains soils.

PURPOSE: Persistent organic pollutants (POPs) are of global concern due to their ubiquitous presence and toxicity. The occurence of polychlorinated dibenzo-p-dioxins (PCDDs), -dibenzofurans (PCDFs), co-planar biphenyls (PCBs), hexachlorocyclohexanes (HCH), dichlorodiphenyltrichloroethanes (DDT), and organochlorine pesticides (OCPs) in forest soil collected from Taurus mountains may have adverse effects on the environment and health. The aim of the study was to investigate the outcome and distribution of POPs in the environment and the possible grasshopper effect along an altitude transect from sea level up to nearly 2,000 m a.s.l at a spatial distance of about 60 km in the southeastern Turkish Mediterranean Sea. METHODS: The samples were collected at a height of 121, 408, 981, 1,225, 1,373, 1,639, and 1,881 m above sea level from Taurus Mountains, Turkey. The results were confirmed using high-resolution gas chromatography-high-resolution mass spectrometry. RESULTS: The levels of the PCDD in forest soil from Taurus Mountains varied from nearly 4 to 12 pg g(-1) dry weight (dw). PCDF concentrations ranged from 2 to 7 pg g(-1) dw. Considerably high DDT levels detected in five stations indicated (3,223-24,564 pg g(-1)) its extensive local application or atmospheric transport. PCB levels were determined between 80 and 288 pg g(-1) dw. HCH concentrations ranged from 141 to 1,513 pg g(-1) dw. The other OCP was between 102 and 731 pg g(-1). CONCLUSION: Although the use of POPs has been banned, our results show that they could still be found in Turkey. Their presence may be attributed to the degradation of pesticides which are newly banned and, as well as to the atmospheric migration and deposition. The lattitude of sampling sites, the chemical, and physical parameters of soil have observed no effect on the fate of POPs in the environment.

The use of olive tree (Olea europaea L.) leaves as a bioindicator for environmental pollution in the Province of Aydin, Turkey.

INTRODUCTION: In this study, olive tree leaves, collected from 50 sampling sites throughout the Province of Aydin, Turkey, were used to estimate level of pollution by measuring Al, As, B, Ba, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sr, and Zn concentrations and calculating pollution factor (PF) values. MATERIALS AND METHODS: After sample preparation, collected leaves were microwave digested, and extracts were analyzed by an inductively coupled plasma-mass spectrometer. RESULTS AND DISCUSSION: The maximum PF values were ≥10 for a number of elements ranging from 11-13 (Al, As, Cr, Fe, Mn, Ni) to >100 for Cu, Li, and Na. Urban-rural and roadside-nonroadside concentration comparisons showed that some of the elements (As, Cu, and Pb) were at significantly higher levels on urban and/or roadside sampling sites. SUMMARY AND CONCLUSION: Correlations and factor analysis showed that there may be common sources for some elements, which included several soil types and anthropogenic activities. Based on the results of the statistical source apportionment, possible sources were narrowed down with help of the constructed elemental concentration maps. In conclusion, utilization of olive tree leaves for biomonitoring and assessment of environmental pollution was shown to be possible in the Mediterranean region where they are indigenous and cultivated.

Baseline of the spatial and temporal metal contamination in Dilek National Park, Turkey.

Dilek National Park in Western Turkey is a protected habitat for several endangered and threatened species. In an attempt to protect the endangered species, the park was classified as a World Heritage Preserve. Even with this change, the animal and flora variety are still at risk from previous metal contamination. Water samples were collected 10 cm below the water surface and sediment from 0-30 and 30-60 cm depth. Inorganic elements were found in all sediment samples. Sodium had the highest aqueous concentration (10,312 mg/L), while Cu, Fe, Mn, and Zn were present at levels significantly lower than the chronic exposure criteria. Zn was the least prevalent (0.4 mg/kg) compound found in the sediment. The highest toxic contaminant concentration was Mg at an average of 1,100 mg/kg. The main contamination source of that seems to be Great Meandrous River. More studies are needed to develop a protection and remediation strategy for Dilek National Park.

Determination of pesticide residues in Turkey's table grapes: the effect of integrated pest management, organic farming, and conventional farming.

Turkey is one of the world's largest producers and exporters of table grapes. Growing social concerns over excessive pesticide use have led to farming to move from conventional to organic practices. Table grapes were collected from 99 different farms in three Aegean regions. Pesticide residues were only detected in farms using conventional agriculture practices while no pesticides were detected in grapes from farms using organic or integrated pest management. A risk assessment model indicated that lambda-cyhalothrin posed the most significant risk at conventional farms.

Pesticide residues in dried table grapes from the Aegean region of Turkey.

Dried grapes make the ideal low-calorie snack. The formation of gray mold during the drying of the grapes can severely decrease production. Pesticides and fungicides are applied to prevent losses due to pests and mold. Dried grapes from 99 farms in the Aegean region were sampled for pesticide residues. Of the 26 pesticides analyzed for, chlorpyrifos methyl, chlorpyrifos ethyl, deltamethrin, lambda-cyolathrin, dichlofluanid, iprodione, and procymidone were detected in the dried grapes. Only seven samples contained residues above the maximum residue limit. It is important to note that pesticide residues were only present in samples originating from vineyards using conventional farming practices.

Evaluation of pesticide contamination in Dilek National Park, Turkey.

National parks are used worldwide as a means to protect the ecological integrity of unique ecosystems. Dilek National Park in western Turkey is a protected habitat for several endangered and severely threatened species. Thirty-seven water and 59 sediment samples were collected and analyzed for pesticides at two different sampling depths. The park is contaminated with 16 different organochlorine pesticides, with more pesticides detected in sediments than in water. The most prevalent pesticides in the 30-60-cm depth were DDT (69.5% of the samples), heptachlor (62.3%), a-endosulfan (55% of samples), and endrin (37%). Lindane isomers were present, but at <30% of the sediment samples. These pesticides could be a long-term contamination source that enters the food web used by the very species the park is trying to protect.

Breed-related plasma disposition of ivermectin following subcutaneous administration in Kilis and Damascus goats.

Many factors related with drug and animals affect the plasma disposition of endectocides including ivermectin (IVM). The aim of the present study was to investigate the breed differences in pharmacokinetics of IVM in goats following subcutaneous administration. Two different goat breeds (Kilis and Damascus goats) were allocated into two treatment groups with respect to breed. The injectable formulation of IVM was administered subcutaneously at a dose rate of 0.2 mg/kg bodyweight. Blood samples were collected before treatment and at various times between 1h and 40 days after treatment and the plasma samples were analysed by high performance liquid chromatography (HPLC) using fluorescence detection. The results indicated that the plasma disposition of IVM was substantially affected by breed differences following subcutaneous administration in goats. The last detectable plasma concentration (t(last)) of IVM was significantly later in Kilis goats (38.33 days) compared with Damascus goats (22.50 days). Although, there were no significant differences on C(max) (10.83 ng/ml vs. 10.15 ng/ml) and t(max) (2.75 days vs. 2.33 days) values; the area under the concentration-time curve-AUC (110.26 ng.d/ml vs. 73.38 ng.d/ml) the terminal half-life-t(1/2lambdaz) (5.65 days vs. 3.81 days) and the mean plasma residence time-MRT (9.31 days vs. 6.35 days) were significantly different in Kilis goats compared with Damascus goats, respectively. The breed-related difference observed on the plasma disposition of IVM between Kilis and Damascus goats could be attributable to different excretion pattern or specific anatomical and/or physiological characteristics such as body fat composition of each breed.

Sex-related plasma disposition of ivermectin following pour-on administration in goats.

The effect of sex difference on the pharmacokinetic profiles of ivermectin (IVM) was investigated following pour-on administration in goats. A total of 12 (six males and six females) Kilis goats were allocated into two treatment groups with respect to sex. The pour-on formulation of IVM was administered topically (pour-on) at dose rate of 0.5mg/kg bodyweight. Blood samples were collected at various times between 1h and 40 days after treatment and the plasma samples were analysed by high-performance liquid chromatography (HPLC) using fluorescence detection. Substantial sex-related differences on the plasma disposition of IVM were observed between males and female goats following pour-on administration. The last detectable plasma concentration of IVM was significantly later in males (16.17 days) compared with female animals (10.67 days). There were no significant differences on C(max), t(max) and the area under the concentration-time curve-AUC values between male and female groups, respectively. However the terminal half-life (t(1/2lambdaz)) and mean plasma residence time (MRT) in male goats (2.35 days and 4.78 days, respectively) were significantly longer compared with female animals (1.42 days and 3.55 days, respectively) and this suggesting that the excretion patterns of IVM in male and female animals are probably different each other.

Contents and sources of DDT impurities in dicofol formulations in Turkey.

BACKGROUND, AIM, AND SCOPE: Dicofol is widely used as a pesticide in agriculture applications. Since dicofol is mainly synthesized from dichlorodiphenyltrichlorethane (DDT), it contains DDT as an impurity. The European Community has forced Prohibition Directive 79/117/EEC to reduce DDT in dicofol formulations. Specifically, DDT content in a dicofol formulation cannot exceed 0.1%. The goal of this project was to determine the DDT content in dicofol formulations used in Turkey. MATERIALS AND METHODS: Samples of all the dicofol formulations in Turkey were collected to quantify DDT and DDT-related compounds. Four replicates were used for each sample. GC/MS/MS was used to analyze p,p' and o,p' isomers of DDT, DDD, and DDE. A HPLC was used to determine p,p'-Cl-DDT concentrations. RESULTS: The total DDT content of the formulated dicofol was found between 0.3% and 14.3%. The concentration of p,p'-DDE ranged from 167 to 1,042 mg kg(-1) in dicofol samples. p,p'-DDT concentrations were found to be 32 to 183 mg kg(-1). The o,p'-DDT level ranged from 2 to 34 mg kg(-1) in the dicofol formulations analyzed. DISCUSSION: It was estimated that 617.8 kg of DDT was released from dicofol. The main impurity was identified as p,p-Cl-DDT. Based on these results, dicofol serves as a continuing source of DDT contamination. CONCLUSIONS: All DDT concentrations in dicofol samples analyzed were higher than the permitted 0.1% level of Prohibition Directive 79/117/EEC. The reduction of dicofol is critical since it serves as a continual source of DDT contamination. RECOMMENDATIONS AND PERSPECTIVES: DDT has been found in soil, water, and air samples. Dicofol has been identified as a contributor to continued DDT contamination in soil and water. More studies are needed to ascertain the source of DDT in the air.

The impact of pesticides toward parrotfeather when applied at the predicted environmental concentration.

Pesticides pose a serious risk for aquatic macrophytes in the environment. They are also detrimental to the rooted macrophytes used in bioassays for assessment. Currently, no data is available for impact of pesticides toward parrotfeather when present at the predicted environmental concentration. The calculated expected environmental concentration was applied to the plants and the effect was compared. Eight of the 18 pesticides showed significantly different impact. All of the other tested pesticides induced a significant change in pigment content of parrotfeather. The RQ values for risk quotient had a value higher than 0.5, so need regulatory action for environment. This study may be the first to evaluate the predicted environmental concentrations reported by pesticide registration in Europe. Additional studies are required to test all pesticides within one group since the compounds tested may depict a wide toxicity level. Furthermore, the tests should include more than one macrophyte, e.g. one rooted and one non-rooted species, in order to provide a better understanding on pesticide toxicity.