Environmental Monitoring and Assessment

, Volume 186, Issue 1, pp 217–228

Assessment of dietary intakes of nineteen pesticide residues among five socioeconomic sections of Hyderabad—a total diet study approach

Authors

  • Agatha Betsy
    • Food and Drug Toxicology Research Centre (FDTRC)National Institute of Nutrition (NIN-ICMR)
    • Food and Drug Toxicology Research Centre (FDTRC)National Institute of Nutrition (NIN-ICMR)
  • SN Sinha
    • Food and Drug Toxicology Research Centre (FDTRC)National Institute of Nutrition (NIN-ICMR)
  • Vishnu Vardhana Rao Mendu
    • Division of Bioinformatics and BiostatisticsNational Institute of Nutrition (NIN-ICMR)
  • Kalpagam Polasa
    • Food and Drug Toxicology Research Centre (FDTRC)National Institute of Nutrition (NIN-ICMR)
Article

DOI: 10.1007/s10661-013-3367-0

Cite this article as:
Betsy, A., Vemula, S.R., Sinha, S. et al. Environ Monit Assess (2014) 186: 217. doi:10.1007/s10661-013-3367-0

Abstract

Total diet study approach was used to assess the dietary intakes of pesticide residues among the select population in Hyderabad. When assessed by a food frequency questionnaire, it was found that the food intakes varied among five socioeconomic sections (SES). Therefore, we intended to compare the intakes of pesticide residues through these foods among the five SES. A total of 195 foods from different markets were collected and analyzed for 19 pesticides. The residues were analyzed with a gas chromatograph and were confirmed with mass spectrometry. About 51 % of the samples were detected with one or more residues. Thirteen out of the 19 residues were present in levels above detection limits in various concentrations. The median concentrations of the residues in all the samples tested, ranged from 0.00010 to 0.33 mg/kg. Highest median concentration was for β-HCH in water samples. Exposures to all the residues were below the respective ADIs at both mean and 95th percentile levels of food intakes with highest estimated dietary intakes (EDIs) of β-HCH in both the cases. The EDIs of β-HCH were the highest among all the residues at both the intake levels among all the SES. The EDIs of β-HCH were significantly higher in lower SES than higher SES possibly due to the consumption of rice cooked in water contaminated with β-HCH. EDIs for other residues did not differ significantly among the five SES.

Keywords

Pesticide residuesDietary intakesTotal dietADIsSocioeconomic sections

Introduction

Around 234 pesticides are registered for use in agriculture in India against various pests and diseases (Singh and Battu 2008). Pesticides mainly function as insecticides (used against insect pests), herbicides (for killing and controlling weeds), fungicides (against diseases), rodenticides, and others. They are classified on the basis of their chemical composition as organophosphate compounds, organochlorines, synthetic pyrethroids, carbamates, bio-pesticides, etc. (CSA, 2007).

Several studies in India have shown persistent occurrence of various organochlorine pesticides (OCPs) like hexachloro-cyclohexane (HCH), dichloro-diethyl-trichloroethane (DDT), aldrin, and dieldrin in different foods and drinking water samples from different parts of India (Battu et al. 1989; Dikshith et al. 1990; Gupta et al. 1982; Kang et al. 2000; Kannan et al. 1992; Kaphalia et al. 1990; Kole et al. 2002; Kumari et al. 2002; Noronha et al. 1980; Singh, 2002; Shukla et al. 2006). HCH isomers (1,2,3,4,5,6-hexachlorocyclohexane) and DDT metabolites [1,1,1-trichloro-2,2 bis (p′ chlorophenyl ethane)] are being used in India for a long time due to their low cost and versatile action against various pests (Kannan et al. 1992). OCPs, being lipophillic in nature, have a tendency to accumulate in fatty tissues as adipose tissues of animals and milk of humans and bovine. High levels of HCH (6,200 ng/g) and DDT (1,200 ng/g) were detected from human milk samples collected from southern India (Tanabe et al. 1990). However, levels of HCH and DDTs were shown to continuously decrease in the bovine milk samples from India (Dethe et al. 1995; Mukherjee and Gopal 1993; Pandit et al. 2002).

The use of these highly persistent OCPs has lead to their sustained presence in trace amounts in soil, water and air leading to their entrance into the food chain. In recent studies, the levels of DDT (and its metabolites ) and HCH (and its isomers) were detected below MRLs in most of the wheat flour (Toteja et al. 2003) and rice (Toteja et al. 2006) samples, and the dietary exposures due to these foods were in minute proportions as compared to ADIs by FAO (FAO, 1986). Although, some of the samples were found to have levels above the MRLs. The authors suggested that they could be due to accidental contact with the chemical. The presence of these chemicals in the staple crops was supposed to be due to their ubiquitous presence in the environment.

Vegetable samples collected at harvest from farmer’s fields around the districts of Hyderabad and Guntur in the south Indian state of Andhra Pradesh, recorded HCH residues above MRL (0.25 ppm) while residues of DDT and cypermethrin were found to be below MRL (3.5 and 0.2 ppm, respectively; CSA 2007). Similarly, yet another study in the Srikakulam district of the same state also showed residues of HCH, DDT, aldrin (including dieldrin), endosulfan, and methyl parathion in vegetables, below the MRLs (Reddy et al. 1998).

Considering the results of studies from Andhra Pradesh and other states and due to lack of recent studies on samples analyzed from southern India for dietary exposures through the diet as whole and not single foods, the present study was undertaken with an objective to check the presence of nineteen pesticides residues, already reported to be present in the foods, and assess their exposures through total diet study approach.

Materials and methods

Study design

Hyderabad is the capital of Andhra Pradesh with a population of 6,809,970 (2011 census). The city of Hyderabad is situated on the Deccan plateau at an altitude of 1,778 ft and occupying an area of 650 km2. Predominant topography of the city is sloping, rocky terrain, and paddy is the major crop grown in surrounding fields. It is divided into 15 circles consisting of 5 SES.

Food consumption data for 5 SES of Hyderabad were obtained. Information about most commonly consumed foods and their markets of purchase was collected by a food frequency interview schedule (FFIS). Selected foods were purchased from the respective markets and were processed as table ready in laboratory and analyzed for select pesticides. The consumption data and the pesticide concentration data were combined to calculate the exposure estimates. The estimates were then compared with the reference toxicological values.

Study population

Population of Hyderabad was divided into 5 SES according to HUDA (Hyderabad Urban Development Authority) classification. A total of 157 households were selected from all the SES and administered a validated food frequency interview schedule (FFIS). The SES were selected by cluster random sampling and households in each SES were selected by systematic random sampling.

Selection of foods

Twenty most commonly consumed foods and water samples were selected for analyzed. Along with them, only the foods which were reported to be detected with the select pesticides and the foods for which no information was available were also selected for analyses. The recently conducted Andhra Pradesh Total Diet Study (APTDS 2010) also provided us with information about the foods already been detected with these select residues. The foods included for analyses were rice, wheat flour, red gram (dhal), tomato, lady’s finger, spinach, amaranth, potato, green chili, milk, mango, fish, and fowl. Drinking water samples which were used for cooking the foods were also collected to calculate the total concentration due to the raw food and the water used for cooking it.

Collection of food samples

Foods were purchased from 13 markets that essentially cater to 5 SES. Food samples representing HIG were collected from supermarkets, those for MIG were procured from retail shops and those representing LIG were collected from rythu bazaar (a market place where farmers directly sell their produce to the consumers). About 1.5 to 2 kg of each food item was collected (to obtain a final edible portion of one kilogram) in sterile zip-lock pouches (for rice, wheat flour, red gram (dhal), tomatoes, lady’s finger, potatoes, fowl, fish, mangoes, and green chilies), sterile jute sacs (for spinach and amaranth, as they were spoiled in zip-lock pouches), and sterile amber glass bottles (for milk and water). Perishable foods such as fowl, fish, water, and milk were transported in ice packing, and other foods were transported at ambient temperature.

Processing of the foods

Edible portions of the foods were processed according to local household practices in table ready form including picking, sieving, washing and cooking. De-ionized water was used for cooking, wherever required. Stainless steel vessels like containers, ladles, covers, spoons, trays, and PTFE chopping boards were used for cooking. No chemical detergent was used for washing to avoid external contamination, and vessels were thoroughly washed with hot water and dried in oven before re-use to prevent cross contamination. The foods were weighed before and after cooking. The amount of water added, temperature, and time required for cooking were already standardized during AP-TDS, and the same conditions were followed for the present study. The cooked foods were cooled, homogenized, and stored in PTFE containers at −20 °C till analyzed. Samples were procured and processed from October 2010 to May 2011.

Selection of pesticides

Nineteen residues were analyzed including one organophosphate compound (chloropyriphos), one synthetic pyrethroid (total cypermethrin), and 17 organochlorine residues and their derivatives. The isomers of HCH; α, β, γ, and δ have different physico-chemical characteristics and toxicity profiles (Herbst 1982). Therefore, they were considered as individual contaminant residues. Selection of pesticides in AP-TDS (2010) was based on several earlier reports from India (AP-TDS, 2010; Battu et al. 1989; Dikshith et al. 1989; Kumari et al. 2003; Pandit et al. 2002; Toteja et al. 2003; Toteja et al. 2006). The use of chlordane, aldrin, dieldrin, and DDT was banned or restricted in India since long during 1960s, but they were included for analysis due to their probable lipophilicity, long-term persistent nature, and lower ADIs. Chlorpyriphos, endosulfan and its derivatives, and cypermethrin are still among the most used pesticides in India (Directorate of Plant Protection et al. 2010).

Analyses of the samples

Extraction of pesticide residues

The cooked wet samples were extracted with acetonitrile (MeCN with 1 % glacial acetic acid) as 1 mL/g (Anastassiades and Lehotey 2003). Fish and fowl samples were additionally cleaned up with C-18. Graphitized carbon black was also tested for cleaning of these samples, but a lower recovery was obtained. All the glassware in contact with the samples were soaked overnight in 1M HNO3 and washed. Glassware was rinsed with pure acetone before use.

Quantification of pesticide residues

Gas chromatograph (Varian 3800) equipped with electron capture detector (GC-ECD) was used for quantification. The oven temperature of GC was at 100 °C for 2 min, programmed from 100 °C to 190 °C at 5 °C per min held for 5 min, and maintained at 250 °C for 4 min. The total run time was 35 min and 1 μL was injected for quantification and confirmation. The detector and injector port temperatures were 300 °C and 270 °C, respectively. A 5 % phenyl 95 % methyl polysiloxone column was used with internal diameter of 0.53 mm, thickness of 0.50 mm, and with 30 m length with split less system. Carrier gas used was Iolar-1 nitrogen (99.999 % purity) and the flow rate was 1.5 mL/min.

GC-MS/MS conditions

GC-MS/MS (Varian Saturn 2200) was used for confirmation of the samples. Mass spectra were recorded in scan mode swith a mass range of 40–500 amu at a scan rate of 1 s/scan. The emission current of the ionization filament was set to 10-lA, which generated electrons at 70 eV of energy. The transfer line, trap, and manifold temperature were set at 270 °C, 170 °C, and 40 °C, respectively (Sinha et al. 2011).

Recovery studies

Recoveries were calculated to check the efficacy of the extraction and were between the limits of 70–120 % for all the non animal food matrices. The percentage of recovery of each pesticide was calculated by comparing the peak area ratio of the spiked standards with those of the pure standards. However, spinach and amaranth showed the lowest mean recoveries (72 % and 75 %, respectively). The recoveries of fish and fowl samples were 67 % and 61 %, respectively. Calibration curves were constructed using 6 different concentrations of spiked pesticides (250, 100, 75, 50, 10, and 5 ng/g in each food matrix) and plotted against the area counts. At least 5 repeat determinations were performed for each concentration on the calibration curve. Calibration standard concentrations encompassed the entire linear range of the analysis. The limit of determination (R2) of 0.9932 was obtained for spiked concentration of all 19 pesticide residues standards on GC (ECD).

Limits of detection (LOD)

LOD was determined at a fortification concentration when the signal-to-noise ratio was 3:1 for each pesticide. The lowest LOD of instrument was obtained as 0.1 ng/g. Lowest limit of method validation (LLMV) was 0.186 ng/g for γ-HCH. The LOD for fortified samples ranged from 1 ng/g for γ-HCH in tomato to 5 ng/g for cypermethrin in spinach samples. The LOD and LOQ were determined on the basis of 1:3 and 1:10 noise-to-signal ratio with minimum possible interferences from the co-extractives.

Calculation of the concentrations was done using the following formulae:
$$ IRF=\left( Area\ IS\times Conc. SC\right)/\left( Conc. IS\times Area\ SC\right) $$
Where,
IRF

is the internal response factor of the GC (ECD)

IS

is the internal standard

SC

is the sample analyte

$$ Concentration\ of\ SC/g\ of\ sample=\left( Conc. IS\times area\ counts\ of\ SC\times IRF\right)/ area\ counts\ IS $$

The samples were confirmed with GC MS/MS (Varian) and were quantified. The area ratio of primary and secondary ions in the MS had to be within 20 % of the theoretical value.

Quality control/quality assurance

Pure standards of individual pesticides were injected to confirm the retention time (RTs), which were matched with those present in samples within ±3 s. One sample from each set of 13 samples was fortified with the mixture of the analytes standard (100 ng/g) and was extracted and run with other samples. Laboratory reagent blanks were treated as actual samples and were run with the set, and the blank value was subtracted from the sample values.

Assessment of dietary intakes

Estimated daily intakes (EDIs) were calculated by combining the consumption data and the concentration data. It was necessary for calculation that the concentrations below detectable limits (BDL) are assigned a numeric value. Concentration of the samples BDL was taken as LOD providing the upper bound (UB) estimates as recommended internationally (WHO 2005). Trace concentrations between the LOD and LOQ were assigned a value equal to half of the LOQ.

Median concentrations were obtained for dietary intake assessments by pooling all the foods from different markets. The median levels of concentrations provide a more realistic and appropriate estimation of long term exposures to residues which are compared with the ADIs, which are lifetime toxicological references (FAO, 1997). Intakes of residues were calculated by multiplying the median concentrations of residues with the consumption data obtained by the FFIS. Exposure estimates were calculated at mean and 95th percentile levels of food consumptions to obtain the normal and worst case scenario, respectively. The estimated intakes for average weight of adult population in India (50 kg) were finally reported as mg/kg bw/day and were compared with the respective ADIs.

Estimated Daily Intakes = ∑ (pesticides average concentration in a food (mg/kg) × daily consumption of the food (g/day/person)/50 kg (average weight of adult population

Statistical analyses

Food intakes were calculated at mean and 95th percentile levels and the concentrations of pesticides in foods were calculated at 25th percentile, median, and 75th percentile. Differences in the food consumptions among various SES were tested by analyses of variance (ANOVA) with post hoc comparison by least significance difference (LSD). The median residue concentrations were compared with the MRL values given by Food Safety and Standards Authority of India (FSSAI, 2011).

Results

Food consumption

Food consumption data were obtained by a validated FFIS for the 5 SES. Cooked rice was consumed in highest quantities among all the foods in 5 SES. There were differences in the eating habits among the five SES in terms of quantities of foods consumed. Cooked rice was consumed more in lower SES, while fruits and vegetables were consumed in higher amounts by HIG and MIG. Food consumption at mean and 95th percentile intake levels is shown in Tables 1 and 2.
Table 1

Mean consumptions (g) of food groups among socio-economic sections

Foods

HIGa mean (SD)

MIGb mean (SD)

LIGc mean (SD)

Ind. laborers mean (SD)

Slum dwellers mean (SD)

Conventional foods

 Cereals

245.53de (85.31)

284.97 (116.94)

285.88 (116.04)

332.70a (136.35)

342.56a (155.50)

 Pulse

40.53 (20.41)

49.61cd (37.39)

33.13b (20.60)

34.96b (27.17)

42.03 (23.69)

 Leafy vegetable

35.00bd (13.19)

49.45acd (20.80)

28.25b (17.97)

14.62ab (3.70)

36.26cd (18.55)

 Root and tubers

106.84 (62.13)

90.39 (40.93)

107.32 (73.77)

80.93 (48.41)

85.44 (45.74)

 Other vegetables

191.09 (106.70)

216.19 (123.26)

156.12 (88.75)

167.87 (88.97)

174.94 (91.46)

 Milk

289.94cde (135.78)

269.74ad (121.57

140.14b (95.67)

118.86 ab (89.63)

172.41cd (109.01

 Fruits

101.52d (100.71)

98.61d (76.55)

52.19 (160.89)

38.93ab (37.90)

69.98 (50.20)

 Oils n fats

32.16 (15.13)

35.13 (12.26)

31.56 (12.07)

28.53 (12.07)

29.12 (14.90)

 Animal products

30.64 (43.15)

36.96 (30.50)

28.87 (64.86)

18.28 (29.02)

35.61 (43.97)

 Sugars

26.06d (12.69)

30.97cde (14.24)

28.62b (26.44)

18.37ab (11.86)

21.88b (9.57)

 Spices

13.72 (4.23)

13.63 (5.99)

12.62 (2.31)

9.20 (4.40)

10.81 (3.23)

Processed foods

 Breakfast cereals

39.93e (28.97)

41.67 (32.55)

12.73d (11.24)

16.24e (11.84)

22.20ad (19.52)

 Ready to eat

34.36cd (19.38)

43.55 (42.73)

27.86a (23.52)

29.00a (33.05)

50.69 (49.69)

 Bakery items

30.00 (30.01)

26.93ce (32.28)

21.67b (20.81)

19.52 (15.98)

36.43bd (25.83)

 Carbonated beverages

38.73c (29.99)

47.95c (46.33)

21.71abde (13.90)

21.62c (27.18)

38.09c (19.08)

 Health drinks

16.06bcde (7.46)

14.91acde (7.50)

13.00ab (8.31)

10.20ab (4.44)

15.78ab (10.44)

Superscripted values are significantly different from the groups (HIG-a, MIG-b, LIG-c, IL-d, SD-e) at α = 0.05

HIG high income group, MIG middle income group, LIG low income group

Table 2

Consumption of various food groups (g) among five socio economic sections in Hyderabad at 95th percentile levels of food intakes

Food groups

HIGa

MIGb

LIGc

Industrial laborers

Slum dwellers

Cereals and millets

378.00

444.00

439.55

539.70

630.60

Pulses

74.25

122.50

65.00

92.85

83.00

Roots and tubers

192.25

157.50

281.20

169.80

160.85

Green leafy vegetables

176.00

157.50

140.35

89.75

145.00

Other vegetables

328.15

475.50

300.10

322.35

338.90

Milk

500.00

458.50

303.95

303.95

408.15

Fruits

286.77

181.25

354.62

141.58

190.87

Fats and oils

56.90

54.50

52.00

48.65

49.40

Eggs and flesh foods

156.65

91.20

209.95

93.00

153.00

Sugars

46.35

51.00

65.00

42.35

37.95

Spices

47.80

46.50

40.00

47.55

50.70

Breakfast cereals

82.30

93.20

31.70

32.00

48.60

Ready to eat

64.40

127.00

61.40

95.75

141.25

Bakery items

87.40

75.00

60.00

49.00

86.35

Carbonated beverages

100.00

150.00

44.90

88.50

84.40

Health drinks

31.35

32.35

27.15

15.80

33.00 HIG

aHigh income group

bMiddle income group

cLow income group

Concentrations of pesticides

Nineteen pesticide residues were analyzed in 12 foods and drinking water samples collected from 13 places in the city. Over a half (51 %) of the samples were detected with various concentrations of 13 pesticides. Concentrations of aldrin, dieldrin, β-endosulfan, endosulfan sulfate, and chlordane isomers (α and γ) were not above the detection limits in any of the tested samples from any of the markets. None of the mango and fowl samples were detected with any pesticide residue. Heptachlor was detected only in 4 samples of lady’s finger. Tomato and spinach samples were detected with maximum number of residues, and fish samples were detected with only the residues of β-HCH, though all the levels were below the MRLs by FSSAI (2011).

The highest median concentration of residues in samples was of β-HCH (0.33 mg/L) in water samples followed by levels of cypermethrin in red gram (dhal) and green chillies (0.293 mg/kg).

Median concentration of β-HCH in milk samples (0.049 mg/L) also was higher than the FSSAI limits of 0.02mg/L.

The HCH and DDT isomers, wherever detected, except in wheat flour samples, were many folds below their respective MRLs. There are no statutory limits for DDT in cereals grains in India. However, the rice samples were detected with trace presence of o′p′ DDE, o′p′ DDD, and p′p′ DDT. Trace residues of lindane and o′p′ DDE were also detected in wheat flour samples exceeding the MRL of zero in milled cereal grains.

Alpha endosulfan was only detected in red gram (dhal) and green chilies samples. Median concentrations of residues in all the tested foods are given in Table 3.
Table 3

Median, 25th, and 75th percentile concentrations (μg/kg or μg/L) of pesticide residues in foods collected from 13 markets in Hyderabad

Foods (N = 13for each food item)

Residues detected

No. of samples detected with residues above detection limit

Median concentration (mg/kg or L)

Range from 25th to 75th percentile concentrations

MRLs by FSSAI (mg/kg or L)

Rice

γ-HCH

3

0.0001

0.0001–0.0001

0.05

o′p′-DDD

4

0.0001

0.0001–0.0001

o′p′-DDE

4

0.0001

0.0001–0.0001

Wheat Flour

γ-HCH

4

0.0044

0.0001–0.0935

Should be absent

o′p′-DDE

4

0.0001

0.0001–0.0001

Red gramdhal

α-Endosulfan

3

0.0001

0.0001–0.0185

0.20

Cypermethrin

11

0.293

0.057–0.44

0.01

Tomato

p′p′-DDE

4

0.0001

0.0001–0.013

3.5

o′p′-DDE

2

0.0001

0.0001–0.0001

3.5

Cypermethrin

7

0.031

0.0001–0.114

3.5

Lady’s finger

Heptachlor

8

0.0001

0.0001–0.069

0.01

o′p′-DDE

4

0.0001

0.0001–0.024

3.5

p′p′DDT

3

0.0001

0.0001–0.0054

3.5

o′p′-DDT

2

0.0001

0.0001–0.0001

3.5

Cypermethrin

3

0.0001

0.0001–0.0001

0.20

Potato

β-HCH

12

0.043

0.034–0.066

1.0

Chlorpyriphos

8

0.006

0.0001–0.012

0.01

Spinach

δ-HCH

9

0.101

0.0001–1.62

3.5

Chlorpyriphos

3

0.0001

0.0001–0.0029

0.2

p′p′-DDE

3

0.0001

0.0001–0.0035

3.5

o′p′-DDD

2

0.0001

0.0001–0.0001

3.5

o′p′-DDD

9

0.067

0.0001–0.33

3.5

o′p′-DDT

11

0.099

0.036–0.33

3.5

Amaranth

Chlorpyriphos

4

0.0001

0.0001–0.0072

0.2

p′p′-DDE

2

0.0001

0.0001–0.0001

2.0

Cypermethrin

3

0.0001

0.0001–0.0001

0.2

Milk

β-HCH

10

0.049

0.011–0.067

0.02

o′p′-DDT

3

0.0001

0.0001–0.029

1.25

Cypermethrin

2

0.0001

0.0001–0.0001

0.01

Water

β-HCH

13

0.33

0.016–0.57

0.001

p′p′-DDT

3

0.0001

0.0001–0.0001

0.01

Fish

β-HCH

7

0.0056

0.0001–0.018

0.25

Green chilli

α-Endosulfan

5

0.0001

0.0001–0.0001

0.20

Cypermethrin

13

0.293

0.13–0.39

3.5

MRLs maximum residue limits

Dietary exposure assessment

Estimated daily intakes (EDIs) were calculated for each of the pesticide residues in all the SES. Intakes were estimated at upper bound concentration levels (i.e., the values BDL were given a numeric value of LOD) and both mean and upper bound (95th percentile) levels for food intake. The estimated dietary intakes of none of the pesticide residues exceeded the ADIs at mean and 95th percentile levels of food intakes. The EDIs for β-HCH were highest among all the residues in all the 5 SES. The highest EDI of β-HCH was found in LIG (22.24 μg/kg bw/day, 44.4 % of ADI) at mean levels and in SD (40.2 μg/kg bw/day, 80.4 % of ADI). The EDIs were highest for β-HCH in SD at 95th percentile intake levels, due to much higher intakes of cooked rice than in other SES. The exposure estimates for β-HCH were significantly higher in lower SES (LIG, IL, SD) than in MIG and HIG at both the levels of food intakes. However, there were no significant differences in the EDIs of other residues among various SES. The EDIs for aldrin were lesser than other residues but percentage of ADIs were higher than many other residues due to its lower ADI (Tables 4 and 5). The contributions of various foods to total EDI of β-HCH are shown in Fig. 1.
Table 4

Estimated daily intakes of pesticide residues and their percent ADIs at mean levels of food intake among five socio economic sections in Hyderabad

Residues

HIGa

MIGb

LIGc

ILd

SDe

μg/kg bw/df

%ADIg

μg/kg bw/d

%ADI

μg/kg bw/d

%ADI

μg/kg bw/d

%ADI

μg/kg bw/d

%ADI

α-HCH

0.005

0.01

0.005

0.01

0.005

0.01

0.005

0.01

0.005

0.01

β-HCH

2.9a

5.99

17.9b

35.8

22.24c

44.48

21.9c

43.73

20.6c

41.27

γ-HCH

0.038

0.08

0.007

0.01

0.006

0.01

0.006

0.01

0.006

0.01

δ-HCH

0.870

1.74

0.007

0.01

0.678

1.36

0.521

1.04

0.982

1.96

Heptachlor

0.006

0.13

0.077

1.53

0.006

0.13

0.006

0.12

0.006

0.12

Aldrin

0.005

5.48

0.006

5.58

0.005

5.34

0.005

5.08

0.005

5.20

Chlorpyriphos

0.037

0.37

0.014

0.14

0.070

0.70

0.053

0.53

0.091

0.91

γ-Chlordane

0.006

1.27

0.007

1.36

0.006

1.30

0.006

1.23

0.006

1.20

α-Endosulfan

0.006

0.11

0.012

0.19

0.018

0.30

0.018

0.31

0.022

0.36

α-Chlordane

0.008

1.28

0.004

1.16

0.006

1.30

0.006

1.23

0.006

1.20

p′p′- DDE

0.252

2.52

0.009

0.09

0.254

2.54

0.194

1.94

1.7

16.97

Dieldrin

0.006

6.38

0.007

6.79

0.006

6.50

0.006

6.15

0.006

5.98

o′p′- DDE

0.25

2.53

0.046

0.46

0.006

0.06

0.006

0.06

0.006

0.06

o′p′- DDD

0.099

0.99

0.007

0.07

1.8

18.05

1.37

13.67

2.7

27.34

β-Endosulfan

0.002

0.04

0.008

0.14

0.011

0.18

0.010

0.17

0.017

0.29

Endosulfan sulfate

0.006

0.11

0.007

0.11

0.006

0.11

0.006

0.10

0.006

0.10

p′p′- DDT

0.260

2.60

0.78

7.84

0.56

5.55

0.532

5.32

0.77

7.72

o DDT

0.22

2.17

0.91

9.14

0.39

3.9

0.309

3.09

0.54

5.42

Cypermethrin

1.21

2.42

0.25

0.49

0.88

1.75

0.73

1.47

1.059

2.12

aHigh income group

bMiddle income group

cLow income group

dIndustrial laborers

eSlum dwellers

fμg/kg bw/d, microgram per kilogram body weight per day

gAcceptable daily intakes

Table 5

Estimated daily intakes of pesticide residues and their percent ADIs at 95th percentile levels of food intake among five socioeconomic sections in Hyderabad

Residues

HIGa

MIGb

LIGc

ILd

SDe

μg/kg bw/df

%ADIg

μg/kg bw/d

%ADI

μg/kg bw/d

%ADI

μg/kg bw/d

%ADI

μg/kg bw/d

%ADI

α-HCH

0.011

0.02

0.011

0.02

0.011

0.02

0.011

0.02

0.012

0.022

β-HCH

4.7

9.42

23

59.31

38.79

77.59

39.04

78.08

40.2

80.40

γ-HCH

0.12

0.23

0.015

0.03

0.014

0.03

0.014

0.03

0.015

0.03

δ-HCH

4.9

9.76

0.015

0.03

3.5

7.01

2.379

4.76

3.8

7.51

Heptachlor

0.012

2.43

0.015

2.99

0.014

2.80

0.014

2.82

0.015

3.05

Aldrin

0.01

10.54

0.011

11.35

0.011

11.07

0.011

11.10

0.012

12.05

Chlorpyriphos

0.075

0.75

0.041

0.41

0.41

4.09

0.26

2.65

0.39

3.90

γ-Chlordane

0.013

2.58

0.015

2.96

0.014

2.80

0.014

2.82

0.015

3.05

α-Endosulfan

0.013

0.21

0.018

0.30

0.049

0.83

0.062

1.04

0.059

0.99

α-5Chlordane

0.013

2.50

0.015

2.96

0.014

2.80

0.014

2.82

0.015

3.05

p′p′- DDE

1.2

11.65

0.015

0.15

1.5

15.34

0.99

9.86

1.6

15.95

Dieldrin

0.012

11.92

0.015

14.80

0.014

14.01

0.014

14.11

0.015

15.27

o′p′- DDE

0.28

2.83

0.015

0.15

0.014

0.14

0.014

0.14

0.015

0.15

o′p′- DDD

0.32

3.20

0.015

0.15

0.014

0.14

0.014

0.14

0.015

0.15

β-Endosulfan

0.013

0.21

0.014

0.23

0.014

0.23

0.014

0.24

0.19

3.13

Endosulfan sulfate

0.013

0.21

0.015

0.25

0.014

0.23

0.014

0.24

0.015

0.25

p′p′- DDT

1

10.03

3.7

37.34

1.2

12.21

1.1

11.00

1.3

12.63

o′p′- DDT

1.2

11.96

2.6

26.48

1.6

16.17

1.2

11.98

1.8

18.09

Cypermethrin

4.4

8.71

0.83

1.66

2.4

4.81

2.7

5.47

2.9

5.92

aHigh income group

bMiddle income group

cLow income group

dIndustrial laborers

eSlum dwellers

fμg/kg bw/d, microgram per kilogram body weight per day

gAcceptable daily intakes

https://static-content.springer.com/image/art%3A10.1007%2Fs10661-013-3367-0/MediaObjects/10661_2013_3367_Fig1_HTML.gif
Fig. 1

Percent contribution to EDIs of β-HCH by various foods in various SES

Discussion

Concentrations of pesticides

The lipophillic nature of the organochlorine chemicals enables them to persist in environment for longer time, even after their discontinued use. They gradually find their way into the food chain leading to several adverse health effects (Kalpana 1999). In India, there is dearth of regular surveillance of the dietary intake estimates of these residues.

The levels of residues like DDT, HCH and aldrin in foods were lesser in the present study as also reported by Bhushan (2006). DDT, HCH, cypemethrin, endosulfan, and aldrin (including dieldrin) in cooked vegetables were lesser than the concentrations shown in earlier samples collected from and around Hyderabad (Reddy et al. 1998) and in Delhi (Bakore et al. 2002). Presence and concentrations of HCH isomers and DDT metabolites were shown to decrease in many foods by Pandit et al. (2002) as compared to earlier study by Kalra et al. (1999). They were still lesser in the present study. Milk samples in our study were detected with higher concentrations of only β-HCH; whereas, in earlier studies (Battu et al. 1989; Kalra et al. 1999; Pandit et al. 2002), other isomers of HCH (α, γ, δ) were also simultaneously found. Similar was the case with DDT metabolites where traces of only o′p′ DDT were found in milk samples in our study while all other metabolites were also detected in earlier studies (Battu et al. 1989; Kalra et al. 1999; Pandit et al. 2002). The trace presence of β-HCH instead of lindane in fish samples as shown in earlier studies (Kannan et al. 1992) may be due to its more persistent nature than lindane and suggests its gradual phase off phenomenon.

All the water samples were detected with only β-HCH, but at levels (54.37 to 431.03 μg/L) were much higher than the permissible limits by the Bureau of Indian Standards (BIS 2004) of 1 μg/L and the desirable limit for pesticides in drinking water is given as “absent.” The levels also exceeded the limits for EU, much lower as the maximum admissible concentration at 0.1 μg/L for individual pesticide and 0.5 μg/L for total allowable pesticide residue. Higher levels of β-HCH in milk and drinking water samples need further investigation.

All vegetables, except spinach, contained lesser concentrations of OCPs when compared with earlier reported studies, probably due to the imposed ban on direct spraying on fruits and vegetables. Leafy vegetables also were reported to be affected with OCP residues (Sasi and Sanghi, 2001); but in the present study, though the vegetables were detected with many residues, they were all in trace quantities, not contributing significantly to the exposures.

The concentrations of HCH and DDT isomers in wheat flour samples were many folds below their respective MRLs. There are no statutory limits for DDT in cereals grains in India. However, the rice samples were detected with trace presence of o′p′ DDE, o′p′ DDD, and p′p′ DDT. Trace residues of lindane and o′p′ DDE were also detected in wheat flour samples exceeding the MRL of zero in milled cereal grains.

Dietary intakes

The dietary intakes of organochlorines like DDT, HCH, aldrin, and diedrin through various foods in India were higher than those in many developed countries (Kannan et al. 1992; Kashyap et al. 1994). The contribution of dairy products to the dietary intake of these residues was very high. In the present study, a higher contribution was that of drinking water. Exposures to organochlorine pesticides (HCH and DDTs) through rice and wheat have been shown to be of very less magnitude by Toteja et al. (2003, 2006).

However, the estimates were higher for β-HCH residue, in the present study, where the foods were made as table ready. Higher estimates of intakes for β-HCH were obtained not only due to the residue content of the raw foods but also of water, which is added to the foods while cooking. Drinking water imparted its residues to the cooked foods and elevated their concentrations even though the raw foods were free from the residues. The drinking water is supplied to the entire city either from river Krishna and or Manjira through municipal supply but the cause of residue levels in drinking water samples needs further investigation. Contamination of ground water in Hyderabad with various concentrations of DDT, beta-Endosulfan, alpha-Endosulfan, and lindane, leading to exposures exceeding the ADIs, has been reported earlier (Shukla et al. 2006).

The amount of water added depended on the amount of food consumed. Population of lower socioeconomic sections in Hyderabad consumed significantly more cooked rice, and hence, more water was used for cooking. Therefore, EDIs of β-HCH by the population of lower SES were much higher than MIG and HIG.

In an earlier study, in Kanpur, India (Shukla et al. 2002), the daily intake of aldrin in average vegetarian diet exceeded ADI by 442 % and in average non-vegetarian diet by 1,500 %. The daily dieldrin intake in average vegetarian diet exceeded ADI by 514 % and in average non-vegetarian diet by as much as 6,000 %. The percent contributions in our study were much lower than the above-mentioned study. In another study (AICRP 2001), 75 % of the vegetarian diets was found to contain various concentrations of different pesticide residues, and DDT and HCH residues were detected in foods from all over the country. About 11 % of diets contained residues exceeding the ADIs. Non-vegetarian samples (72 %) were detected with HCH, DDT, endosulfan and chlorpyrifos, and 15 % was exceeding the ADIs.

When comparing the trend of two residues common for analyses in our study with those reported from the first Hong Kong first TDS (HKTDS, 2012), the organophosphate residue, chlorpyphos, and the synthetic pyrethroid, cypermethrin, were mostly found in vegetables. Cypermethrin in Cameroon TDS (Gimmou et al. 2008) and chloropyriphos in French TDS (Nougadère et al. 2012) were also frequently present in vegetables. These results were similar to our findings indicating similarity in their usage among the southern Asian countries. EDIs for chloropyriphos in the present study were lower than the ADIs, but the percent contribution to ADIs was greater than those observed in the HKTDS (0.01–0.041 % of ADI). The percent contributions to ADIs for cypermethrin also were higher (0.4–8.71 % of ADI) in our study as compared to the HKTDS (0.3–1 % of ADI). Unlike in the French TDS, where dieldrin and heptachlor were found to be probable reasons for chronic risk at upper bound levels of residue concentrations in foods, these residues were not detected above the limits in our study and their EDIs (when calculated with LOD as the numeric for concentration) also were well below the ADIs. Another study indicated reduction in ΣDDT in the total diet but EDI levels exceeding the ADIs for lindane, mainly due to consumption of milk (Battu et al. 2005).

However, in the present study, cooking oil was not analyzed which could have affected the EDIs as earlier studies (Kannan et al. 1992) have shown high concentrations of HCH and DDT isomers in groundnut oils and ghee. The amount of cooking oils consumed also was found to be higher than many other foods.

Conclusions

Most of the residues were present at below detectable levels in the most commonly consumed foods in various SES and those present above detection levels were in trace quantities with an exception of levels of β-HCH in water and milk. Absence of aldrin, dieldrin, heptachlor, chlordane, and α-HCH from the food samples suggests clearance of these residues from local food chain, though it was evident that the use of other residues like α-endosulfan, chlorpyriphos and cypermethrin is on rise. EDIs below the respective ADIs of residues suggest low chronic dietary exposures of the population of Hyderabad. However, levels of β-HCH in water and milk samples prompt the need for further investigation.

Acknowledgments

This work was supported by a grant provided by the Indian Council of Medical Research (grant number 09-FD06) and University Grants Commission, Govt. of India provided the fellowship (Senior Research Fellowship) to AB.

Copyright information

© Springer Science+Business Media Dordrecht 2013