Evaluation of pesticide residues in open field and greenhouse tomatoes from Colombia

Food Control 30 (2013) 400e403

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Short communication

Evaluation of pesticide residues in open field and greenhouse tomatoes from Colombia Carlos Ricardo Bojacá a, *, Luis Alejandro Arias b, Diego Alejandro Ahumada c, Héctor Albeiro Casilimas c, Eddie Schrevens d a

Departamento de Ciencias Básicas, Facultad de Ciencias Naturales e Ingeniería, Universidad Jorge Tadeo Lozano, Calle 22 No. 3-30, Módulo 15 Mezzanine, Bogotá, Colombia Departamento de Ciencias Biológicas y Ambientales, Facultad de Ciencias Naturales e Ingeniería, Universidad Jorge Tadeo Lozano, Carrera 4 No. 22-61, Módulo 7A, 4
Piso, Bogotá, Colombia c Centro de Bio-Sistemas, Facultad de Ciencias Naturales e Ingeniería, Universidad Jorge Tadeo Lozano, P.O. Box: A.A. 140196, Chía, Colombia d Department of Biosystems, Faculty of Bioscience Engineering, Katholieke Universiteit Leuven, Geo-Institute, Celestijnenlaan 200 E, 3001 Heverlee, Belgium b

a r t i c l e i n f o

a b s t r a c t

Article history: Received 13 June 2012 Received in revised form 3 August 2012 Accepted 21 August 2012

The presence of 17 pesticide residues was determined in just-picked tomatoes coming from open field and greenhouse farms in Colombia. Pesticide residues were quantified through a multiresidue method using ultra performance liquid chromatograph coupled to mass spectrometer. The results give no clear indication about which farming system is producing the most contaminated tomatoes. While the share of open field samples violating the maximum residue limits (MRLs) was higher, the presence of more than one pesticide per sample was detected in a higher number of greenhouse samples. Results showed that all positive samples for acephate exceeded the recommended MRL, indicating indiscriminate use of this insecticide. In both farming systems, the pre-harvest intervals are not respected due to the management practices applied and the continuous ripening of the fruit, once the harvest starts. The results of the present study confirm the need for a monitoring program, actually inexistent, focused in the food commodities consumed locally. Ó 2012 Elsevier Ltd. All rights reserved.

Keywords: Colombia Tomato Pesticide residues Farming systems

1. Introduction The exposure to pesticides has become a public health issue in Colombia, showing a steady increase in human toxicity occurrences due to pesticides, reaching 8016 cases in 2010 (Páez et al., 2011). Previous studies have shown that population directly exposed to pesticides, such as those involved in the manufacture or application processes, will accumulate these compounds into the bloodstream at harmful levels (Hernández, Guerrero, Cubillos, & Salazar, 1986; Idrovo, 2000). However, little is known about the risk posed by the edible products to the final consumer. Until recently, due to the lack of evidence, the presence of pesticides in food was considered of low risk. During the last decade, the chemical harmlessness was included as a priority issue for the country through national policies. Nevertheless, the existence of monitoring programs for pesticide residues is focused on export products while excluding most of the food commodities * Corresponding author. Tel.: þ57 1 2427030x1704; fax: þ57 1 2826197. E-mail addresses: [email protected] (C.R. Bojacá), luis.arias@ utadeo.edu.co (L.A. Arias), [email protected] (D.A. Ahumada), [email protected] (H.A. Casilimas), eddie.schrevens@ biw.kuleuven.be (E. Schrevens). 0956-7135/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.foodcont.2012.08.015

consumed locally. This situation is in contrast to nationwide monitoring programs already established long time ago in neighboring countries such as Brazil (Jardim & Caldas, 2012). Fruit and vegetables are mainly consumed raw or semiprocessed and it is expected that they contain higher pesticide residue levels compared to other food groups of plant origin (Claeys et al., 2011). Tomato is one of the staple foods in Colombia, with an annual per capita consumption of 9.4 kg (Ulrichs, Fischer, Büttner, & Mewis, 2008). This horticultural commodity is a basic component of the Colombian diet and is used almost on a daily basis as part of raw or home cooked preparations. Tomato production is spread countrywide and a production of 519,843 t was harvested in 14,128 ha during 2010 (Agronet, 2010). Colombian tomato is cultivated under two predominant production systems: one being small processing-type “chonto” tomato grown in open field conditions using sub-optimal practices. The other, beefsteak-type tomato, is grown under greenhouse conditions in fairly high-intensive systems (i.e., adopting climate control, fertigation, pruning and training systems). Although reliable information is lacking, it is estimated that greenhouse production system is employed in 30% of the cultivated area (Miranda et al., 2009).

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The present work aims to determine the presence of pesticide residues in tomatoes grown in Colombia for fresh consumption, collected from the two most important production systems: open field and greenhouse, considering the farm gate as the sampling location. 2. Material and methods 2.1. Study zones Santander is a department of Colombia located in the central northern part of the country. Agriculture is developed in a series of mountainous valleys and hills, with open field tomato as one of the main horticultural products of the region. Tomato is produced in rotation with other crops such as corn, cucumber, sweet pepper or pea. The Alto Ricaurte province is the most important greenhouse tomato production region in Colombia. This province comprises a mountainous valley located in the Eastern range of the Colombian Andes, in the central area of the department of Boyaca. Due to its mild climate, this region has seen a rapid expansion in greenhouse tomato production for the last decade. 2.2. Samples collection The tomato samples were collected from selected farms located in the two study zones. During the 2011 harvest period, six farms from Santander and ten from Boyaca were followed up, and a sample of tomatoes was collected at each harvest date. A total of 26 samples (1 kg each) from Santander and 105 from Boyaca were packed in plastic bags and submitted to the laboratory for the pesticides residues analysis. Following the commercial practice, the tomato samples were analyzed within the 48 h after picking, without considering any storage period. The differences in the number of samples collected on each study zone arise from two factors. The first one is related with the number of farms considered on each site, while the second one was the length of the harvesting period. Open field tomatoes are harvested during a much shorter time due to the determinate growth characteristic of the cultivars. On the other hand, tomato cultivars used for greenhouse production have an indeterminate growth point allowing a longer production period. On average, the harvesting period in Santander was 62 days while in Boyaca was 107 days. 2.3. Analytical procedures The multiresidue method, developed by Ahumada and Zamudio (2011a), was used to determine the concentration residues of 17 pesticides of the collected samples. The basic characteristics of the pesticides analyzed are presented in Table 1. The extraction procedure is based on the QuEChERS method, and the determination of the components was performed using ultra performance liquid chromatograph coupled to mass spectrometer. Pesticide reference standards were obtained from Dr. Ehrenstorfer GmbH (Augsburg, Germany) and Chemservice (West Chester, PA, USA). Stocks were prepared in a concentration around 500 mg ml1, using either, acetonitrile or methanol as solvent. All the solvents used were HPLC grade supplied by J.T. Baker (Phillisburg, NJ, USA). The QuEChERS Restek Q-SepÔ salt kits were used in the extraction process and the Restek dSPE Q-SepÔ adsorbent kits were employed in the clean-up procedure. The chromatographic analyses were performed in an ultra-high speed liquid chromatograph Shimadzu ProminenceÔ coupled to an LCMS-2020 mass selective detector (Maryland, CA, USA). An

401

Table 1 The usage, CAS number, maximum residue limit (MRL) and limit of quantification (LOQ) of the pesticides analyzed. Name

Use

CAS No.

MRL (mg kg1)a LOQ (mg kg1)

Acephate Carbendazim Carbofuran Chlorfenapyr Cymoxanil Difenoconazole Dimethoate Dimetomorph Hexaconazole Imidacloprid Indoxacarb Metalaxyl Methomyl Methoxyfenozide Pyrimethanil Spinosad Thiocyclam

Insecticide Fungicide Insecticide Insecticide Fungicide Fungicide Insecticide Fungicide Fungicide Insecticide Insecticide Fungicide Insecticide Insecticide Fungicide Insecticide Insecticide

30560-19-1 10605-21-7 1563-66-2 122453-73-0 57966-95-7 119446-68-3 60-51-5 110488-70-5 79983-71-4 138261-41-3 173584-44-6 57837-19-1 16752-77-5 161050-58-4 53112-28-0 168316-95-8 31895-22-4

0.02 0.5 0.02 0.05 0.2 2.0 0.02 1.0 0.1 0.5 0.5 0.2 1.0 2.0 1.0 1.0 0.01

a

0.04 0.01 0.02 0.49 0.6 0.009 0.02 0.01 0.097 0.279 0.02 0.01 0.02 0.03 0.011 0.1 0.15

According to EU pesticide residues database.

ABN2ZE Peak Scientific (Billerica, USA) nitrogen generator was employed to provide the dryer stream in the ESI source. The chromatograph was equipped with a SIL20A UFLC 7673 Shimadzu (Maryland, CA, USA) automatic sampler, a binary high-pressure pump, online degasification system and an oven to control the column temperature. The analyses were performed with a Shimpack C18 column (60 mm  2 mm i.d., 2.1 mm particle size). The acquisition, control and data processing were performed using the Lab Solutions version 3.5 software. A modified version of the QuEChERS method (Ahumada & Zamudio, 2011b) was carried out in order to obtain pesticide extracts by the following procedure. In a centrifuge tube, 10 g of previously homogenized sample were weighed, 15 ml of solvent were poured into it and then it was manually shaken by 1 min. The extraction solvent consisted of acetonitrile and acetic acid 1% (v/v). Thereafter, 6 g of anhydrous MgSO4 and 1 g of sodium acetate were added, and it was shaken again. The tube was centrifuged to 4500 rpm for 5 min and 10 ml of the supernatant (solution A) was measured using a pipette and then transferred to a 15 ml centrifuge tube. In the case of the clean-up procedure, 25 mg of PSA (primary/ secondary amine) and 150 mg of anhydrous MgSO4 were added for each extract milliliter of solution A. Afterward, it was shaken for 30 s and centrifuged by 2 min at 4500 rpm. Finally, the supernatant was filtered through a 0.22 mm PTFE filter (Ahumada & Zamudio, 2011a).

3. Results and discussion The results for the present study include all pesticide residues at or above the analytical limit of quantification. The individual results for each pesticide and tomato type are presented in Table 2. 3.1. Open field tomatoes The results for open field tomatoes showed that pesticide residues were found in 73.1% of the samples analyzed. Furthermore, 10 out of the 17 pesticides analyzed were detected for this tomato type. Of the six farms considered in this system, only one did not report any pesticide residue on the harvested tomatoes. During the studied period, at least one pesticide was detected on each sampled date. Out of the 26 samples collected, 15 samples reported pesticide concentrations above the maximum residue limits (MRLs).

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Table 2 Concentration median and ranges (mg kg1) of the detected pesticide residues present in open field and greenhouse tomatoes. Active ingredient

Acephate Carbendazim Carbofuran Cymoxanil Dimetomorph Hexaconazole Imidacloprid Indoxacarb Metalaxyl Methomyl Methoxyfenozide Pyrimethanil Thiocyclam

Open field

Greenhouse

Positive samples

%

Median (mg kg1)

Range (minemax)

Samples exceed MRL

Positive samples

%

Median (mg kg1)

Range (minemax)

Samples exceed MRL

9 1 5 e e e 1 3 1 1 2 3 1

34.6 3.9 19.2

0.05 0.01 0.025

0.04e0.34 0.01 0.02e0.04

9 0 4

17 34 e 1 8 9 17 13 13 3 e 41 4

15.9 31.8

0.04 0.01

0.04e0.33 0.01e0.25

17 0

0.9 7.5 8.4 15.9 12.2 12.2 2.8

1.05 0.01 0.17 0.30 0.02 0.01 0.195

1.05 0.01 0.1e2.23 0.28e0.485 0.01e0.11 0.01e0.08 0.02e0.32

1 0 7 0 0 0 0

38.3 3.7

0.01 0.125

0.01e0.335 0.1e0.2

0 4

3.9 11.5 3.9 3.9 7.7 11.5 3.9

0.28 0.05 0.075 0.06 0.03 0.01 0.18

0.28 0.02e0.14 0.075 0.06 0.03 0.01 0.18

0 0 0 0 0 0 1

The most frequent detected pesticide was the insecticide acephate and the concentration found on all samples exceeded its MRL. Following acephate, the insecticide carbofuran was detected in 19.2% of the samples being the second most frequently pesticide found in open field tomatoes. On average, the positive samples for acephate and carbofuran were above their MRL (0.02 mg kg1 for both) by 450 and 140%, respectively. Single occurrences of imidacloprid, metalaxyl, methomyl and thiocyclam were reported but the concentrations found were below their MRLs, exception made for the insecticide thiocyclam. The positive sample for thiocyclam exceeded the MRL by 1800%. As presented in Table 3, half of the analyzed samples contained residues of one pesticide while the detection of two (15.4%) or three pesticides (7.7%) was less frequent. 3.2. Greenhouse tomatoes The share of greenhouse tomato samples with at least one pesticide (71.4%) was similar to the one found for open field tomatoes. Pesticide residues were detected for tomatoes of all production units at least in one sampled date. However, the share of samples exceeding the MRLs (27.6%) was almost half of the one reported for open field tomatoes. Pesticide residues were detected throughout the harvesting period for the production units considered. The fungicide pyrimethanil and the insecticide carbendazim were, by far, the most frequent detected pesticides. Almost all the samples positive for acephate, cymoxanil, hexaconazole or thiocyclam exceeded the MRLs, on average, by 355.9, 525, 606.1 and 1375%, respectively. The occurrence of more than one pesticide in a single sample was more frequent in greenhouse than open field tomatoes. Furthermore, it was observed a higher frequency of detected residues from two pesticides in a positive sample than one. Eight samples contained more than three pesticides at the same time (Table 3). The results for acephate, in both farming systems, suggest an indiscriminate use of this pesticide. This insecticide is widely used against the two species of whitefly, Bemisia tabaci and Trialeurodes vaporariorum, each one affecting open field and greenhouse plants, respectively. Acephate residue in vegetables has been attracting Table 3 Number of pesticides detected per individual sample as a function of tomato type. No. of findings

0

1

2

3

4

5

Open field Greenhouse

7 30

13 23

4 29

2 15

0 6

0 2

much attention because the residue of its metabolite, methamidophos, may be hazardous to human health (Li, 2005). According to Chuanjiang et al. (2010), it is expected that acephate should degrade faster in greenhouse than open field conditions, based on its half-lives of 1.07 and 1.36 days, respectively. The results do not give an indication about which farming system is producing the most contaminated tomatoes. While in open field tomatoes the share of samples violating the MRLs was higher, more greenhouse tomato samples exhibited the presence of more than one pesticide at a time. These results are a direct consequence of the pest management practices applied on each system. Under open field conditions, pesticides accumulation on fruits can decrease due to the direct effect of rainfall and solar radiation. On the other hand, despite of the higher yields that can be achieved (Cantliffe et al., 2001), conditions in greenhouses are often conducive to outbreaks or arthropod pests and plant disease that acquire excessive use of pesticides (Osman, Al-Humaid, AlRehiayani, & Al-Redhaiman, 2011). Override the pre-harvest intervals increases the potential health risk by impeding the reduction of the residue levels within acceptable limits (Cengiz, Certel, Karakas¸, & Göçmen, 2007). Once the harvest starts, fruits ripen permanently without giving any chance to growers of respecting the pre-harvest intervals due to the pest pressure. In developing countries, including Colombia, due to several socio-cultural and technical reasons, diffusion and acceptance of new production approaches (e.g. organic production, low-input agriculture, agroecological systems) among farmers has been very slow (Kaushik, Satya, & Naik, 2009). In Colombia, the Instituto Colombiano Agropecuario (ICA) is the competent authority to regulate the life cycle (manufacture, use and disposal) of pesticides in agriculture. According to the national database of registers, published periodically by ICA, four of the analyzed pesticides are not registered in Colombia. Another four pesticides do not have register for its specific use in tomato. All the non-registered products in Colombia were detected in the open field samples while half of these pesticides were found in greenhouse samples. These irregularities denote the absence of control by the authorities coupled with deficient technical support. The results of the present study confirmed the need for a monitoring program that covers the food commodities consumed locally. Critical literature about pesticide use and markets states that exports are pesticide intensive while national market crops are not. However, national market vegetables can be more pesticide intensive than export vegetables, as demonstrated by Galt (2008). On the other hand, monitoring programs for pesticides residues in

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developing countries are often limited due to the lack of resources, trained personnel, specialized equipment and rigorous legislation is not in place (Hjorth et al., 2011). 4. Conclusions Tomatoes grown in Colombia under open field and greenhouse production systems were collected for pesticide residues analysis. The presence of pesticide residues in tomatoes for local consumption is more common than expected despite of the production system employed. However, for open field and greenhouse tomatoes, pesticide residues exceeding the MRLs were detected in 53.9% and 27.6% of the samples, respectively. Out of the 17 pesticides considered, the concentrations found in all positive samples for the insecticide acephate exceeded the MRLs for both types of tomatoes. The results stress the need for the establishment of a monitoring program of pesticide residues, oriented toward locally consumed vegetables such as tomato. Acknowledgments The Flemish Interuniversitary Council (gs1) (VLIR), through the project “Multidisciplinary assessment of efficiency and sustainability of smallholder-based tomato production systems in Colombia, with a roadmap for change” code ZEIN2009PR364, funded this study. References Agronet e Colombian Ministry of Agriculture and Rural Development. (2010). Statistics for the agricultural sector. Available at http://www.agronet.gov.co Accessed 27.04.12. Ahumada, D. A., & Zamudio, A. M. (2011a). Análisis de residuos de plaguicidas en tomate mediante el uso de QuEChERS y cromatografía líquida ultrarrápida acoplada a espectrometría de masas. Revista Colombiana de Química, 40(2), 227e246. Ahumada, D. A., & Zamudio, A. M. (2011b). Development of a method for determination of thiocyclam and other pesticides by UFLC/MS. 3rd Latin American Pesticide Residue Workshop Food and Environment, 8e11 May 2011, Montevideo, Uruguay.

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Cantliffe, D. J., Shaw, N., Jovicich, E., Rodriguez, J. C., Secker, I., & Karchi, Z. (2001). Passive ventilated high roof greenhouse production of vegetables in a humid, mild winter climate. Acta Horticulturae, 559, 195e201. Cengiz, M. F., Certel, M., Karakas¸, B., & Göçmen, H. (2007). Residue contents of captan and procymidone applied on tomatoes grown in greenhouses and their reduction by duration of a pre-harvest interval and post-harvest culinary applications. Food Chemistry, 100(4), 1611e1619. Chuanjiang, T., Dahui, L., Xinzhong, Z., Shanshan, C., Lijuan, F., Xiuying, P., et al. (2010). Residue analysis of acephate and its metabolite methamidophos in open field and greenhouse pakchoi (Brassica campestris L.) by gas chromatographye tandem mass spectrometry. Environmental Monitoring and Assessment, 165(1e 4), 685e692. Claeys, W. L., Schmit, J. F., Bragard, C., Maghuin-Rogister, G., Pussemier, L., & Schiffers, B. (2011). Exposure of several Belgian consumer groups to pesticides residues through fresh fruit and vegetable consumption. Food Control, 22(3e4), 508e516. EU pesticide residues database. EU pesticide residues database for all the EU-MRLs. Available at Accessed 20.04.12. Galt, R. E. (2008). Pesticide in export and domestic agriculture: reconsidering market orientation and pesticide use in Costa Rica. Geoforum, 39(3), 1378e1392. Hernández, L., Guerrero, E., Cubillos, F., & Salazar, F. (1986). Niveles sanguíneos de insecticidas organoclorados en varios grupos de población colombiana. Revista Colombiana de Ciencias Químicas y Farmacológicas, 45(1), 49e58. Hjorth, K., Johansen, K., Holen, B., Andersson, A., Christensen, H. B., Siivinen, K., et al. (2011). Pesticide residues in fruits and vegetables from South America e a Nordic project. Food Control, 22(11), 1701e1706. Idrovo, A. J. (2000). Vigilancia de las intoxicaciones con plaguicidas en Colombia. Revista de Salud Pública, 2(1), 36e46. Jardim, A. N. O., & Caldas, E. D. (2012). Brazilian monitoring programs for pesticide residues in food e results from 2001 to 2010. Food Control, 25(2), 607e616. Kaushik, G., Satya, S., & Naik, S. N. (2009). Food processing a tool to pesticide residue dissipation e a review. Food Research International, 42(1), 26e40. Li, J. (2005). Pre-harvest intervals of some pesticides in fruits and vegetables in China. Northwest Horticulture, 18(4), 34e35. Miranda, D., Fischer, G., Barrientos, J. C., Carranza, C., Rodríguez, M., & Lanchero, O. (2009). Characterization of productive systems of tomato (Solanum lycopersicum L.) in producing zones of Colombia. Acta Horticulturae, 821, 35e45. Osman, K. A., Al-Humaid, A. I., Al-Rehiayani, S. M., & Al-Redhaiman, K. N. (2011). Estimated daily intake of pesticide residues exposure by vegetables grown in greenhouses in Al-Qassim region, Saudi Arabia. Food Control, 22(6), 947e953. Páez, M. I., Varona, M., Díaz, S. M., Castro, R., Barbosa, E., Carvajal, N., et al. (2011). Evaluación de riesgo en humanos por plaguicidas en tomate cultivado con sistemas tradicional y BPA (Buenas Prácticas Agrícolas). Revista de Ciencias, 15, 153e166. Ulrichs, C., Fischer, G., Büttner, C., & Mewis, I. (2008). Comparison of lycopene, bcarotene and phenolic contents of tomato using conventional and ecological horticultural practices, and arbuscular mycorrhizal fungi (AMF). Agronomia Colombiana, 26(1), 40e46.