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Tomato production in Brazil
Poor working conditions and high residues 
threaten safety 

A study of pesticide use on tomatoes in the Northern State of Pernambuco, Brazil, indicates high exposure to pesticide workers and poor application methods which threaten the ecology of the area. Researchers Adelia Araujo and Lia Augusto report on their findings which show high levels of banned pesticide residues in many tomato samples.

Tomatoes contain high levels of banned pesticide residues.

Tomatoes are grown widely in the Pernambuco region, North-eastern Brazil, and cultivation occurs across most of South America. Pernambuco accounts for 35% of Brazil’s production – the second largest producing region. Tomatoes form a major part of the diet in Brazil. This study focused on 32 tomato producers, covering about 150 hectares, who between them employ around 500 agricultural labourers. Detailed interviews were conducted with 49 women and 110 men who worked on the farms. Over a quarter (26%) were under 18 years old.
    While approximately 70% of the US$30 billion pesticide market are consumed in industrialised countries, the majority of acute and fatal poisonings occur in developing countries1,2. The adverse impacts on human health, damage to the environment, destruction of ecosystems and effect on the quality of life are not calculated as part of the cost of pesticide use. In Brazil, these problems are compounded by rural poverty and inequalities in distribution of land ownership.
    In the past, agricultural policy in Brazil required farmers to buy pesticides using rural credit, which included a specific pesticide quota for each loan. This credit obligation, in conjunction with intense advertising by pesticide manufacturers, has resulted in an enormous increase in the distribution and use of pesticides in the country. The lack of technical capacity to enable small-scale farmers and farm workers to apply pesticides safely, and the absence of any health or environmental monitoring, creates a serious problem for the country. 
    Although pesticides represent the major health problems in rural areas, little specific information is available on the serious and chronic effects of human exposure to these products3,4. The health surveillance programme in Brazil offers little to rural workers: with minimal support from the departments of health, agriculture, labour or environment, they receive no supervision, access to information, training or pesticide education. Rural workers are extremely vulnerable to exploitation, exacerbated by poverty and high levels of illiteracy.
    Serious pesticide poisoning cases have been relatively well documented in some regions of Brazil5 but are totally unregistered in others. In 1993, 10,223 general cases of serious poisoning were registered in the North East of the country, of which 1,069 were in the State of Pernambuco. However, in this agriculturally productive State, only 307 cases were related to crop and livestock production, and there were no registrations of occupational accidents6, reflecting an urban bias in the statistics, and a lack of health facilities to treat and document poisoning in rural areas.
    The poor working conditions of the women and men farm labourers in Brazil often lead to multiple exposures to a range of products resulting in serious health problems, with a wide variety of symptoms, which jeopardise the diagnosis of poisoning7.

The study
Before the study began, meetings to clarify the process were held with people involved socially and economically in the region. The 159 women and men workers were selected randomly. Interviews were based on a questionnaire and supplementary discussions, which covered the structure of their work, quality of life and medical history. Women were asked to provide information on all pregnancies, birth conditions, and survival of offspring. Standardised tests adapted for the Brazilian population were used to assess disease and to identify minor psychiatric problems and alcoholism.
    According to data from the Ministry of Agriculture, a wide range of chemical products are used in tomato production – potentially 53 different active ingredients. Because of the high cost of analysing residues, the study was limited to those which produce known risks to human health and the environment, and focused on 21 organochlorine and 10 organophosphate (OP) insecticides and ethylenethiourea (ETU), a breakdown product of ethylene dithiocarbamate (EBDC) fungicides (such as maneb, mancozeb). A total of 32 active ingredients were analysed (see below).


Children applying hazardous pesticides.

Working conditions
The majority of workers were involved in all phases of the tomato production process, but 32 (29%), all men, worked only as sprayers. Of the men who sprayed, 22% had received no training and only around 13% had some information about the products used. Pesticides were mixed without protection by workers with no technical competence: 64% did not make use of any personal protective equipment; and 46% did not obey the re-entry period. The average work time for a pesticide sprayer was three years. 
    Of those interviewed, 75% had two to five other family members working in the fields, including children under 18. Of the married men, 50% reported that their wives also participated in work. Some of the women interviewed were heads of household, and others had husbands working on the farms. Family income was less than US$320 per month for 86% of the families interviewed. Work contracts were not negotiated collectively, and on average temporary workers received less than U$110 per month – with none receiving more than U$300 per month. The majority (73%) worked from 8-10 hours daily and 26% of the workers did not take a weekly break. As few as 1.3% were officially employed; 98% did not have social security, and only 15% were union members. Women were even less likely than men to be permanently employed, have social security or be union members.

Table 1: Health impacts on workers
Symptoms  % suffering
Itching of skin, eyes and nose; or fever  36%
Skeletal/muscular problems (joint pain)  36%
Dizziness, numbness in limbs, alterations in 
sleep patterns, and vomiting 
Nausea during application  28%
Digestive system problems  28%
Sensory organ problems  25%
Cardiovascular problems  18%
Respiratory system problems  13%
Poisoning that required first-aid treatment  13%
Urinary-genital system problems  11%
Reproductive effects
Levels of miscarriage  71%
Incidence of mental/physical disability in
Neuro-psychological symptoms  42% 
The majority of workers interviewed suffered from more than one symptom. 

Hazards in the work and home environment
Producers reported using a wide range of pesticides (42 different products, of which 59% were insecticides – see table 2), which surprisingly included organochlorine insecticides, banned for use on tomatoes in Brazil, and the use of other products of unknown origin or cancelled registration. The majority of products used were acquired in local businesses and co-operatives.
    A great number of pesticide containers were left in the fields, disregarding disposal recommendations. Women washed the pesticide application equipment, generally in the work environment, without protective clothing or without observing the recommended three-fold washing process. 

Poisoning assessment
Many of the pesticides used were hazardous organochlorine and OP insecticides. Of the workers interviewed, 13% suffered some type of acute poisoning that required first-aid treatment; 28% reported nausea during application of pesticides; and the majority experienced some symptoms immediately after exposure. 36% reported health problems related to the immune system (frequent itching of skin, eyes, and nose; or fever); 36%, skeletal/muscular problems (pains in joints); 33%, central and peripheral nervous system problems (dizziness, numbness in superior limbs, alterations in sleep patterns, and vomiting); 28%, digestive system problems; 25%, sensory organ problems; 18%, cardiovascular problems; 13%, respiratory system problems; and 11%, with urinary-genital system problems (see table 1).

Reproductive effects
Of the women workers, 32% reported being pregnant more than five times, 53% reported having prenatal examinations, 97% reported that they were not poisoned by pesticides during pregnancy. Almost three-quarters of the women (71%) reported miscarriages, and 11% reported having mentally and/or physically impaired offspring.

Neuro-psychological symptoms
Symptoms of minor psychiatric disturbances were observed in 44% of women and 56% of men surveyed (in the general Brazilian population, the prevalence is 5% to 15%). In a further test 20% of those observed, principally men, demonstrated symptoms of alcoholism.

Pesticide residues in tomatoes
Analysis of residues
The 32 tomato samples analysed for residues were selected on a random basis. Because of the high costs involved, the laboratory could only and covered around 30% of all cited products. A multi-residue method8 for the analysis of the 21 organochlorine and nine OP insecticides was implemented and validated, as were specific methods for the residue analysis of the OP methamidophos9 and ETU10. The organochlorines tested were: aldrin, dieldrin, endrin, HCB, heptachlor, heptachlor epoxide, mirex, p-p’-DDE, o-p’-DDD, p-p’-DDD, o-p’-DDT, p-p’-DDT, a-chlordane, ß-chlordane, a-HCH, ß-HCH, g-HCH, g-HCH, a-endosulfan, ß-endosulfan and endosulfan sulfate. Organophosphates tested, in addition to methamidophos and ETU, were dichlorvos, fosdrin, diazinon, fenchlorvos, pirimiphos methyl, parathion methyl, malathion, fenitrothion, parathion ethyl.
    The results of the laboratory analysis showed the maximum residue limits (MRLs) are regularly exceeded: methamidophos in 25% of the samples, and ETU in 78%. ETU can cause goitres (a condition in which the thyroid gland is enlarged), birth defects and cancer in exposed experimental animals11. ETU has been classified as a probable human carcinogen by the US EPA12. The organochlorine insecticide, endosulfan, which is banned for use on tomatoes was detected in 28% of samples at levels of up to 510 parts per billion. Out of 32 samples, eight samples contained methamidophos, in 25 contained ETU and in nine contained endosulfan, all of them were above the Brazilian MRL.
    The high resolution gas chromatography analysis also indicated the presence of other compounds, possibly organochlorines, although they could not be identified and quantified by the adopted methodology. It is nevertheless evident that grave problems exist regarding food safety. In Brazil, there are standards regarding the use of pesticides in agriculture; yet, with the exception of a few states with effective supervision, adherence to standards conflicts directly with the social and economic reality. The contribution of laboratory analysis is important only when accompanied by policies that will lead to change.

The challenge for the authorities responsible for pesticide control lie in introducing: 

  • monitoring of health and environmental impacts of pesticides
  • eliminating the adverse impacts of pesticides on the health of rural workers
  • implementing methods of agricultural production which are less dependent on chemicals

The results from this study indicate that the Pernambuco State ministry of health and municipal governments should develop a pilot project for monitoring exposure to pesticides. The project should include strategies to address the elements developed in this study, such as tests to identify serum cholinesterase activity, and to monitor and diagnose cases of poisoning by OP and carbamate pesticides.
    The government needs to implement regulations which require workers involved in this risk-laden activity be registered, trained and have access to local health units. Information which conveys the risks of exposure to pesticides should not rely heavily on the printed word because of the high number of illiterate and semi-illiterate workers. Monitoring initially should focus on those who are more exposed, such as the men spraying pesticides and the women washing equipment, although impacts on the wider environment should also be addressed. 
    It is important to introduce education on the hazards of pesticides and good agricultural practices in the school curriculum as many children accompany their family members into the fields. Children need to receive information regarding the safe use of pesticides and technological alternatives, thus creating a new mind-set in the use of these products and of agricultural sustainability.
    The state of Pernambuco has the resources to use existing public health laboratories to establish a toxicology network, which would support the integrated actions of environmental quality and human health control. However, the first step for pesticide control must be a revision of the State laws on pesticides, which were developed prior to the Constitution of 1988. New governmental policy must call for the integration of State agencies linked to health, agriculture, labour and environment and to agencies providing the means for implementation.

Table 2: Products used in tomato production
Active ingredient  Trade names  No. of farms using product/s*
acephate  Orthene (IF)  1
benomyl  Benlate (F)  3
biological control (verticillium lecannii)  Vertimec (B)  10
captan  Orthocide (F)  5
cartap  Cartap (IC)  7
chlorfluazuron  Atabron (I)  1
copper oxychloride  Funguran (Cu), Recop (Cu), Reconil (Cu),Cupravit (Cu),
cyfluthrin  Baythroid (IP)  8
cymoxanil  Curzate  1
cypermethrin  Cymbush (IP)  1
deltamethrin  Decis (IP)  10
dicofol  Kelthane (C)  3
endosulfan  Thiodan (C)  1
fenpropathrin  Meothrin (IP)  1
lambdacyhalothrin  Karate (I)  21
lufenuron+difenzoquat metilsulfate  Match (I)  12
malathion  Meltron  1
mancopper+mancozeb+maneb+zineb  Dithane (F)  14
mancozeb+maneb  Manzate (F)  10
metalaxyl  Ridomil (F)  4
methamidophos  Tamaron (IF), Hamidop (IF)  14
methomyl  Lannate (IC)  2
parathion-methyl  Folidol (IF)  4
permethrin  Talcord (I), Ambush (IP) 20
phenthoate  Elsan (IF)  11
profenofos  Curacron (IF)  4
tebuconazole  Folicur (F)  4
teflubenzuron  Nomolt (I)  2
trifluralin  Trigard (I)  1
Unknown active ingredient  Agrimicina (A)  1
Formicida Shell (C)  1
Piredan (IP)  1
Simirex  1
Sumidan (IP)  5
Thiobel (IC)  3
*There is no information from six of the farms
(I) insecticide; (IF) organophosphorous insecticide; (IC) carbamate insecticide; 
(IP) pyrethroid insecticide; (C) organochlorine insecticide; (F) fungicide; (H) herbicide; 
(Cu) cupric product; (B) biologic product; (A) antibiotic. 

The authors are grateful to the Fundação de Amparo à Ciência e Tecnologia de Pernambuco (FACEPE) and to the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPQ) for financial support, and to colleagues of the State Ministry of Health for collaboration in various phases of this study.

1. Public Health Impact of pesticides used in agriculture, World Health Organization (WHO), Geneva, 1989, WHO/UBC document 86.926.
2. Pesticides and Health in Americas, Pan American Health Organization, Washington, 1993, Environmental Series No. 12.
3. Op. cit. 1.
4. Op. cit. 2.
5. FAD Zambrone, Contribuição ao estudo das intoxicaçóes na região de Campinas, São Paulo, Medical Science Faculty, UNICAMP, 1992.
6. EG Garcia, Segurança e saúde no trabalho rural com agrotóxicos: contribuição para uma abordagem mais abrangente. São Paulo, Public Health Faculty, USP, 1996.
7. Ibid.
8. Analytical methods for pesticide residues in foodstuffs-Part I, General Inspectorate for Health Protection, Dutch Ministry of Public Health, Welfare and Sport, Amsterdam, 1996.
9. LMS Zavatti and R Abakerli, Determination of pesticide residues in tomato fruits with a multiresidue method. In: Uses and environmental safety in Latin America, 1Þ, São Paulo, 
IUPAC/GARP workshop on pesticides, Book of Abstracts, São Paulo, IUPAC/GARP, 1996, p.78. 
10. L Bolzoni; A Sannino and M Bandini, Determination of ethylenethiourea and propylenethiourea in tomato products and in fruit purees, Food Chem., 1993, 47: 299-302.
11. Mancozeb, Extoxnet, Pesticide Management Education Program, Cornell University, 5123 Comstock Hall, Ithaca, NY, US, 1992.
12. US EPA, EBDCs: notice of intent to cancel and conclusion of Special Review, 1992.

Lia G. S. Augusto works for FIOCRUZ /CPqAM/ Núcleo de Estudos em Saúde Coletiva (NESC), Recife-PE, Brazil; and Adélia C. P. Araújo works for the Instituto Tecnológico do Estado de Pernambuco (ITEP), Laboratório de Toxicologia, Av. Prof. Luís Freire, 700 50740-540 Recife-PE, Brazil.

[This article first appeared in Pesticides News No. 46, December 1999, pages 12-14]

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