Determination of pesticide and phthalate residues in tea by QuEChERS method and their fate in processing.

In this study, the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was applied for the analysis of the multiclass pesticide residues of 12 organochlorines (OCs), 9 organophosphates (OPs), 11 synthetic pyrethroids (SPs), 4 herbicides, 6 phthalates in raw tea (loose tea, branded tea and herbal tea), and tea infusion in 4 different containers (glass cup, earthen cup, plastic bag and disposal cup). In loose tea and branded tea residues, malathion (0.257 and 0.118 mg kg-1), cypermethrin (0.065 and 0.030 mg kg-1), and fenvalerate (0.032 and 0.030 mg kg-1) were detected, respectively. In herbal tea, residues of only cypermethrin (0.053 mg kg-1) and fenvalerate (0.045 mg kg-1) were detected. Tea infusion samples contained in a plastic bag were found to be contaminated with only dibutyl phthalate (DBP) (0.038 mg kg-1). Disposable cup was found to be contaminated with DBP (0.026 mg kg-1) and diethyl phthalate (DEP) (0.004 mg kg-1). Further, to know the processing behavior of pesticides, the spiked raw tea was subjected to tea infusion at different brewing times (2, 5, 10 min). The analysis demonstrated that dimethoate, dichlorvos, and malathion had shown more than 10 % of translocation at 5 min of brewing time. Further brewing for 10 min revealed the reduction in concentration of pesticides. Leaching of phthalate residues from different plastic containers was also studied at 10, 30, and 60 min. DBP, benzyl butyl phthalate (BzBP), and di-2-(ethylhexyl) phthalate (DEHP) were leached in the tea infusion samples packed in plastic bags. On the other hand, in disposable cups, leaching of DBP, DEP, and dimethyl phthalate were found. The concentration of phthalate residues increased with retention time. Pesticide and phthalate contaminants were recorded at low quantities in few samples only.

Determination of 17 organophosphate pesticide residues in mango by modified QuEChERS extraction method using GC-NPD/GC-MS and hazard index estimation in Lucknow, India.

A total of 162 samples of different varieties of mango: Deshehari, Langra, Safeda in three growing stages (Pre-mature, Unripe and Ripe) were collected from Lucknow, India, and analyzed for the presence of seventeen organophosphate pesticide residues. The QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method of extraction coupled with gas chromatography was validated for pesticides and qualitatively confirmed by gas chromatography-mass spectrometry. The method was validated with different concentrations of mixture of seventeen organophosphate pesticides (0.05, 0.10, 0.50 mg kg(-1)) in mango. The average recovery varied from 70.20% to 95.25% with less than 10% relative standard deviation. The limit of quantification of different pesticides ranged from 0.007 to 0.033 mg kg(-1). Out of seventeen organophosphate pesticides only malathion and chlorpyriphos were detected. Approximately 20% of the mango samples have shown the presence of these two pesticides. The malathion residues ranged from ND-1.407 mg kg(-1) and chlorpyriphos ND-0.313 mg kg(-1) which is well below the maximum residues limit (PFA-1954). In three varieties of mango at different stages from unpeeled to peeled sample reduction of malathion and chlorpyriphos ranged from 35.48%-100% and 46.66%-100% respectively. The estimated daily intake of malathion ranged from 0.032 to 0.121 µg kg(-1) and chlorpyriphos ranged from zero to 0.022 µg kg(-1) body weight from three different stages of mango. The hazard indices ranged from 0.0015 to 0.0060 for malathion and zero to 0.0022 for chlorpyriphos. It is therefore indicated that seasonal consumption of these three varieties of mango may not pose any health hazards for the population of Lucknow, city, India because the hazard indices for malathion and chlorpyriphos residues were below to one.

Disposition and acute toxicity of imidacloprid in female rats after single exposure.

Single dose of imidacloprid (IMI-20mg/kg bodyweight) was orally administered in female rats. Its disposition along with two metabolites 6-chloro nicotinic acid (6-CNA) and 6-hydroxy nicotinic acid (6-HNA) was monitored in organs (brain, liver, kidney, and ovary) and bodily fluids (blood, urine) at 6, 12, 24 and 48h and faeces at 24 and 48h. Maximum concentration (Cmax) of IMI and metabolites in each organ and bodily fluid occurred after 12h. Area under curve (AUC) of IMI ranged from 35 to 358µg/ml/h; 6-CNA: 27.12-1006.42µg/ml/h and 6-HNA: 14.98-302.74µg/ml/h in different organs and bodily fluids. Clearance rate of IMI was maximum in ovary followed by kidney, liver, brain, faeces, blood and urine. Percent inhibition of acetyl-cholinesterase (AChE) was comparable in brain and Red Blood Cells (RBC) at 6-48h which suggests the RBC-AChE as valid biomarker for assessing IMI exposure. It is evident that IMI was absorbed, metabolized, and excreted showing increased level of serum enzymes like Glutamic oxaloacetic transaminase (GOT), Glutamic pyruvic transaminase (GPT) and biochemical constituents like billirubin and Blood Urea Nitrogen (BUN) at 48h. These data suggest that IMI is widely distributed, metabolized and induced toxicology effects at 20mg/kg bodyweight to female rats.

Analysis of imidacloprid residues in fruits, vegetables, cereals, fruit juices, and baby foods, and daily intake estimation in and around Lucknow, India.

A total of 250 samples-including fruits, fruit juices, and baby foods (50 samples each), vegetables (70 samples), and cereals (30 samples)-were collected from Lucknow, India, and analyzed for the presence of imidacloprid residues. The QuEChERS (quick, easy, cheap, effective, rugged, and safe) method of extraction coupled with high-performance liquid chromatographic analysis were carried out, and imidacloprid residues were qualitatively confirmed by liquid chromatography-mass spectrometry. Imidacloprid was not detected in samples of fruit juices and baby foods. It was, however, detected in 38 samples of fruits, vegetables, and cereals, which is about 15.20% of the total samples. Of samples of fruits, 22% showed the presence of imidacloprid, and 2% of samples showed residues above the maximal residue limit. Although imidacloprid was detected in 24% of vegetable samples, only 5.71% showed the presence of imidacloprid above the maximal residue limit. However, 33% of cereal samples showed the presence of imidacloprid, and about 3% of samples were above the maximal residue limit. The calculated estimated daily intake ranged between 0.004 and 0.131 µg/kg body weight, and the hazard indices ranged from 0.007 to 0.218 for these food commodities. It is therefore indicated that lifetime consumption of vegetables, fruits, fruit juices, baby foods, wheat, rice, and pulses may not pose a health hazard for the population of Lucknow because the hazard indices for imidacloprid residues were below one.

Lung function impairment in women exposed to biomass fuels during cooking compared to cleaner fuels in Uttar Pradesh, India.

A national survey has shown that approximately 75-80% use of fire wood and chips, 10% of dung cake rural women in Uttar Pradesh, India. Considering the respiratory health risk of biomass fuel exposure to women, a cross sectional study was conducted to elucidate the relationship between cooking smoke and lung function impairments. The present study showed significant decline in air flow limitation based on reduced PEFR (3.69 | sec(-1)) and FEV1 (1.34 | sec(-1)) in women cooking with biomass fuels compared to PEFR (4.26 | sec(-1)) and FEV1 (1.73 | sec(-1)) in women cooking with cleaner fuels. The noxious gases and particles generated from biomass fuels during cooking reported in earlier studies may be the reason for the slight decline in airway status PEFR (3.69 | sec(-1)) and lung volumes FEV1 (1.34 | sec(-1)). The higher mean bio-fuels exposure index (52.5 hr-yrs) can attribute to reduced lung function in rural women.

Toxicological impact of technical imidacloprid on ovarian morphology, hormones and antioxidant enzymes in female rats.

Technical imidacloprid was evaluated for its effect on ovarian morphology, hormones and antioxidant enzymes in female rats after 90 days oral exposure. Luteinizing hormone (LH), follicle stimulating hormone (FSH) and progesterone levels were estimated in serum of rats and activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and level of reduced glutathione (GSH) and lipid peroxidation (LPO) were estimated in ovary after oral administration of imidacloprid (5, 10, and 20mg/kg/day) for 90 days. Decreased ovarian weight together with significant patho-morphological changes in follicles, antral follicles and atretic follicles were observed at 20mg/kg/day. Imidacloprid at 5 and 10mg/kg/day has not produced any significant changes in ovarian morphology, hormones and antioxidant status of ovary. However 20mg/kg/day dose has produced significant alterations in the levels of LH, FSH and progesterone. Similarly significant changes in SOD, CAT, GPx, GSH, and LPO were observed at 20mg/kg/day dose level. Therefore, it is concluded that imidacloprid at 20mg/kg/day dose level has produced significant toxicological impact on ovary of female rats as evident by pathomorphological changes, hormonal imbalance and generating oxidative stress and can be considered primarily as Lowest Observed Effect Level (LOEL) for chronic study.

A 90 days oral toxicity of imidacloprid in female rats: morphological, biochemical and histopathological evaluations.

A 90 days oral toxicity study of imidacloprid was conducted in female rats with doses of 0, 5, 10, 20mg/kg/day. Decrease in the body weight gain was observed at 20mg/kg/day and at necropsy the relative body weights of liver, kidney and adrenal was also significantly increased at this dose level. No mortality occurred during treatment period while food intake was reduced at high dose level. In clinical chemistry parameters high dose of imidacloprid has caused significant elevation of serum GOT, GPT, glucose and BUN and decreased the activity of AChE in serum and brain. The spontaneous locomotor activity was also decreased at highest dose exposure where as there were no significant changes in hematological and urine parameters. The brain, liver and kidney of rats exposed with high dose of imidacloprid had showed mild pathological changes. Based on the morphological, biochemical, hematological and neuropathological studies it is evident that imidacloprid has not produced any significant effects at 5 and 10mg/kg/day doses but induced toxicological effects at 20mg/kg/day to female rats. Hence, 10mg/kg/day dose may be considered as no observed effect level (NOEL) for female rats.

Level of organochlorine pesticide residues in dry fruit nuts.

The use of pesticides on cash crops and exportable food commodities had always been a serious concern. Fruits form one of the important constituents of human diet, in that they give one third of the requirement of calories, vitamins, and minerals. This study has been carried out to determine the level of organochlorine pesticides namely HCH, DDT and Endosulfan in raw fruit nuts. Nuts have proteins and high level of fat content. These properties of nuts attract organochlorine pesticides to accumulate. The analysis of organochlorine pesticide residues in commonly used dry fruits like Cashewnut, Walnut, Coconut, Chilgoza, Chironji, Makhana, Resins, Apricot, Almonds, Date palm, Pistachio nut collected from local market of Lucknow India has indicated presence of very low level of HCH (0.007-1.328 mg kg(-1)), DDT(ND-0.140 mg kg(-1)) and Endosulfan (ND-0.091 mg kg(-1)). There are no MRL values established for nuts in the country. This finding is based on a smaller number of samples, which however suggest that the presence of low level of DDT, HCH and Endosulfan might be due to environmental rather than direct exposure.

Clinical, biochemical and neurobehavioural studies of workers engaged in the manufacture of quinalphos.

59 workers exposed to different chemicals during the manufacture of quinalphos, an organophosphate pesticide (OP) and 17 control subjects were studied. Despite similar blood acetylcholinestarase (AChE) levels in both the exposed and control subjects, a significant number of exposed subjects had altered plantar and ankle reflexes. Higher nervous functions such as memory, learning and vigilance were also found to be affected in these subjects. These findings were attributed to chronic low dose combined exposure to different chemicals used/formed in the manufacture of quinalphos. The study raises the doubt that monitoring of AChE alone among subjects engaged in the manufacture of OP pesticides may not be an adequate safeguard as regards to their health.

Phototoxicity of quinalphos under sunlight in vitro and in vivo.

The phototoxicity of quinalphos (QP) under sunlight was studied by investigating skin sensitization, mouse tail and ear swelling tests and generation of activated oxygen species (AOS). Quinalphos, at an oral dose of 5 mg/kg to the mouse, did not produce any change in water content of the tail, but produced ear swelling under sunlight (60 min). The pesticide did not produce any skin sensitization reaction when applied on depilated skin of guinea pigs (100-500 microg/cm2) and irradiated under sunlight (60 min). Furthermore, the compound produced a significant amount of AOS such as singlet oxygen (1(O2)) and superoxide anion radical (O2- under sunlight. The production of AOS was both concentration (1-20 microg/ml) and irradiation time (0-40 min)-dependent. The generation of AOS was also confirmed by using quenchers of singlet oxygen (sodium azide and DABCO) and superoxide anion radical (SOD).

Membrane damaging potential of photosensitized riboflavin.

Riboflavin upon exposure to UV and visible radiations has been shown to produce active oxygen species. The present work deals with erythrocyte membrane as model system to study the damaging potential of photosensitized riboflavin. Membrane preparations (2.5 mg protein/ml) following exposure to sunlight in presence of riboflavin for different time intervals revealed significant inhibition of ATPases, p-nitrophenyl phosphatase and acetylcholinesterase. Considerable increase in lipid peroxidation was caused by the photosensitized riboflavin. Quenching studies using specific scavengers indicated remarkable inhibition. The production and identification of reactive oxygen species by photosensitized riboflavin and their possible involvement in membrane damaging effect has been discussed.

Photosensitizing potential of benzanthrone.

In skin-photosensitization studies on guinea-pigs benzanthrone induced significant erythema and oedema, depending upon the doses both of benzanthrone and of sunlight or artificially simulated UVA radiation. Maximum sensitization and delayed tanning response on the guinea-pig skin were observed 24-36 hr after irradiation. Photosensitized benzanthrone was found to produce significant amounts of singlet oxygen in vitro, as assessed by the bleaching of N,N-dimethyl-p-nitrosoaniline. As with haematoporphyrin and rose bengal, both of which are potent generators of singlet oxygen, the production of singlet oxygen by benzanthrone was dependent on both the concentration of the test chemical and the dose of solar radiation. Benzanthrone also produced a significant yield of superoxide anion radicals on exposure to simulated solar radiation or sunlight. Photosensitized benzanthrone induced photohaemolysis of rat erythrocytes and lipid peroxidation of erythrocyte ghosts, in vitro, probably largely through involvement of singlet oxygen (1O2). The rate of lipid peroxidation by photosensitized benzanthrone was inhibited by 64-80% with 1,4-diazabicyclo(2,2,2)octane and sodium azide, 15% with superoxide dismutase but was not affected by mannitol and sodium benzoate. Equimolar concentrations of haematoporphyrin and rose bengal also produced considerable photohaemolysis of erythrocytes and lipid peroxidation in erythrocyte ghosts; in both cases rose bengal was the most active and benzanthrone the least active of the three compounds.