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Nicaragua pesticide exposure and poisoning survey

Pan-American Health Organization (PAHO) studies occupational and environmental aspects of pesticide exposure. In Nicaragua, PAHO has been working with the Ministry of Health and others since 1994 on a pesticide health project (named PLAGSALUD) which identifies problems, influences policy and raises public awareness. The PLAGSALUD team has carried out a series of assessments of pesticide impacts. Stephanie Williamson examines the findings from one of the most traditional farming areas in Nicaragua.

Small-scale farmer filling his spray tank from the stream for applying methamidophos on cabbage. Pesticide contamination of water sources is a key concern in vegetable, tobacco and coffee production. Photo Stephanie Williamson

A high proportion of very poor subsistence farmers growing maize and beans live in the Madriz Department in the north of Nicaragua. This predominantly agricultural zone is characterized by coffee and tobacco production for export. Madriz only joined the PLAGSALUD programme in 1998 and the team were concerned about the high levels of under-reporting of poisonings and the inadequate reporting procedures in the Department's health agencies. In 1999 they drew together existing records covering the period 1995-98 and carried out interviews with health and agriculture professionals, pesticide retail outlets and their staff and with local government and civil society organizations, in order to get a better understanding of the pesticide exposure situation.

Poisoning cases and recording problems
Table 1 gives a summary of the key categories of recorded poisoning events which PLAGSALUD compiled from different sources. Total acute poisonings recorded over these four years were 202, increasing from 24 in 1995 to 73 in 1998, indicating a disturbing 200% increase between these dates. PLAGSALUD estimate that over a quarter of actual poisoning cases do not enter the official records, although they may be treated at local hospitals or health centres. The majority of those affected were men and their incidence of poisonings per 10,000 individuals was almost double that of women. 

Table 1. Poisoning in Madriz, Nicaragua, 1995 – 98

Category

Poisoning events

%

Total cases reported

202

100

Deaths

37

18.3

Males poisoned

129

63.9

Females poisoned

73

36.1

Age group:

 

 

  0-14 years

27

13.4

  15-49 years

173

85.6

  50+ years

2

1.0

Cause:

 

 

  accidental exposure

35

17.3

  attempted suicide

63

31.2

  occupational exposure

3

1.5

  suicide

28

13.9

  no data

73

36.1

Pesticide group:

 

 

  organophosphates

94

46.5

  carbamates

18

8.9

  pyrethroids

10

5.0

  herbicides

26

12.9

  organochlorines

5

2.5

  rodenticides

2

0.9

  fungicides

1

0.5

  phosphine

21

10.4

  ‘no data’

25

12.4

Compiled by PLAGSALUD from different sources.


    The recording system revealed that the biggest single category of poisoning records, 36%, did not include data on cause or type, while suicides and attempted suicides accounted for 45% between them. Work-related poisoning only made up 1.5% of recorded cases but the recording system was not able to distinguish which of the accidental and ‘without data’ categories might, in fact, have been due to occupational exposure.
    Organophosphates accounted for most fatalities, followed by herbicides and carbamates. Of the cases where a named product was responsible, Gramoxone (paraquat) came top, with 24 poisonings directly attributed to its use (including five deaths), followed by Gastoxin (phosphine) with 21 cases, of which two were fatal. The PLAGSALUD team noted that records mainly referred to pesticide groups, rather than common or trade name, and they spotted several incorrect classifications. They were also concerned with the discrepancies between different sources of poisoning case information in national and local registers and estimated that up to six out of every ten cases did not get recorded in the National Epidemiological Vigilance database or in the Health Ministry’s Pesticide Programme register.

Exposure and risks in pesticide retail outlets and workplaces 
Nicaragua’s Ministry of Agriculture and Forestry is responsible for registration and control of retail and wholesale suppliers of pesticides. In the whole of Madriz Department, there are 13 recorded pesticide outlets, including the Health Ministry’s local vector control office. Most are retail distributors of agricultural products. The PLAGSALUD team talked to their managers and staff about their working practices and health and safety issues when handling or storing pesticides. Worryingly, 18% of these shops stored the pesticides along with food items, in one case, a pesticide shop was located next to a small grocery store with only a sheet of plywood separating the two premises.
    These outlets tend to adjust their inventory according to demand and did not accumulate excess stocks which required disposal. However, the vector control office admitted that they disposed of stocks in a rubbish tip on site and the team noticed out-of-date products lying around there. When trying to estimate pesticide usage in volume, the team used sales records supplied by these outlets, which only detail the most frequently purchased items. The Ministry of Agriculture and Forestry’s figures only correspond to total pesticide importation at national level. There are no studies with data on the volume of pesticides used at departmental level. PLAGSALUD’s estimates for pesticide sales in Madriz indicate that approximately 12,700 litres and kilos of OPs (malathion, methamidophos and chlorpyrifos) were sold in 1998; 8,150 litres of herbicides (Gramoxone and 2,4-D), 1,300 kg of carbofuran and 8,000 aluminium phosphide tablets. From 1996 the Health Ministry stopped using malathion for vector control and substituted pyrethroids, mainly cypermethrin.
    In terms of occupational health and safety, the team observed that none of the retail outlets displayed any kind of hazard or caution signs, and 91% of them did not provide any protective equipment to their staff. 36% of retail staff said they regularly repacked or decanted pesticides and 72% admitted that they did not always wash their hands after handling pesticides. 

Nicaraguan organic farmer

Don Arnulfo Corrales has been growing 3 ha of coffee for 15 years on his medium-sized mixed farm in the northern coffee zone of Matagalpa. He first started cutting back on agrochemicals in 1997, as a group leader of the Aranjuez Valley Co-operative when they collaborated with CATIE’s (Centre for Research and Education in Tropical Agriculture) IPM training programme in Nicaragua, funded by NORAD (Norway’s development assistance).

The training sparked Don Arnulfo’s interest because he could not afford to keep buying pesticides and wanted to improve the quality of his coffee. Through the training, he and fellow co-op members learnt how to scout each week to assess insect pests and diseases and how to use Beauveria bassiana fungus to control coffee berry borer beetle Hypothenemus hampeii. He has managed to greatly reduce this pest and his bushes suffer much less from brown leaf spot disease Cercospora coffeicola. For him it is important to scout regularly to see how his different coffee plots are growing. Unfortunately, he had not been able to use Beauveria in 2000 because he could not find where to buy it. Don Arnulfo adapted the weekly scouting to a monthly regime because the young man who helped him has left and, as an old man, it is tricky to see small insects. He prefers to do most of the pest management work, rather than hire labour. 
    This includes regular pruning, selecting the best branches, and rejuvenating his plots bit by bit. Via a different training course, Don Arnulfo learnt how to use calcium sulphate as a natural fungicide. Several farmers are using it now and have had good results with leaf spot diseases. He also produces compost from coffee pulp, almost 36 tonnes in 1999. He grows Canavalia bean for ground cover and nitrogen fixing and mills the bean pods to produce a soil enrichment, and brews biofertilizer. Don Arnulfo enjoys being more self-sufficient and experimenting, but complains that other farmers cannot always be bothered. The economic benefits of giving up chemicals are less tangible, however. He is sure his input costs are lower than those using agrochemicals, especially as he makes his own fertilizer. While Don Arnulfo’s coffee is fully organic, he was not able to sell it at a higher price in 1999 because buyers failed to turn up. To produce good coffee he estimates you need to put in double the work and with certification costs of US$210/ha you need to get a much higher price. In his view, the market is what is really discriminating against campesino farmers now. He produces 1600 kg/ha coffee beans in a good year and about half that amount in a poor year (the national average is less than 300kg/ha) but unless the price is reasonable, Don Arnulfo is asking ‘what’s the point of that extra effort?’

This interview was conducted in October 2000 as part of CABI Bioscience consortium’s evaluation of the CATIE IPM-Agroforestry Programme, in collaboration with Programme staff and funded by NORAD.

Pesticide use patterns
The study did not carry out a comprehensive survey of agricultural pesticide use but made use of local data provided by the National Institute for Agricultural Technology (INTA), local municipalities and coffee producers’ associations. At national level there has been a marked upward trend in pesticide imports in the last few years and PLAGSALUD believe that pesticide use will increase further in Madriz, as figures show significant increases in most crop acreages sown. This is despite the perception of many public interest groups and people in the Environment Ministry that pesticide use is relatively limited in Madriz compared to other parts of the country, particularly by poor farmers who have difficulty affording agrochemical inputs. PLAGSALUD point out that their findings indicate trends and the results do not imply that the theoretical volumes or product usage estimated are necessarily used in practice. From INTA’s recommended products and application rates per area for different crop types and cultivation systems and municipal data on crop acreages, they drew up a list of potential pesticide use in Madriz. Taking the example of traditional manual bean cultivation, as practised by local subsistence farmers on around 4,200ha in the Department, if these farmers were following standard recommendations they could be applying over 42,000 kg/l of OPs (malathion and methamidophos). Data from the retail stores and interviews showed that 50 different insecticides, herbicides, fungicides, rodenticides, molluscicides and fumigants were in active use in Madriz, including two active ingredients listed under the Prior Informed Consent (PIC) process for importation of hazardous chemicals (methamidophos and parathion methyl). Tobacco, which is grown by large-scale, commercial operations, is the highest crop consumer of pesticides, with over 22kg/l per ha of formulated fungicides, insecticides and herbicide recommended and an average of 35 applications per season.

Environmental impact concerns
Local municipalities, NGOs and the Environment Ministry are all worried about the negative effects of pesticide use in Madriz. From interviews and field visits, PLAGSALUD identified concrete problems in water contamination, soils and signs of undesirable changes in agro-ecosystems. 
    Pesticide application equipment is washed directly in rivers and waterholes, some of which are sources of drinking water for a large proportion of the poorer inhabitants of Madriz. Particular hazards are posed by tobacco and vegetable production since these crops are cultivated year-round, receive frequent applications of pesticides and are often grown very close to water sources and houses. Key incidents of concern were: 

  • Vegetable crop and coffee pulp waste, containing high levels of pesticides, was regularly dumped into certain rivers
  • Contamination of one particular river where cabbage and tomato were grown and frequently sprayed within 200m of the riverbank 
  • Three cases of river and domestic well contamination where these were situated close to tobacco fields

Empty pesticide containers are often found discarded in fields and on riverbanks. In Somoto district where soils are already very poor, herbicide accumulation in the soil leaves bare soil in the off-season, leading to increased soil erosion. Pesticide contamination is also reducing the amount of soil organic matter and changing soil chemistry and pH. The local municipalities cited whitefly outbreaks due to pesticide resistance: disruption of natural enemies; loss of soil productivity; and increased weed problems as local environmental problems related to pesticide dependency. The Environment Ministry’s national pollution control strategy highlights agrochemicals as a priority for Madriz Department.

Concrete actions
To address the negative impacts of pesticide use PLAGSALUD recommended that local, intersectoral pesticide commissions (CLIPs), which already exist in many other parts of the country, be set up in the most affected municipalities, and coordinated initially by the Ministry of Health’s Pesticide Programme officer. CLIPs should involve all the interested stakeholders: Ministries of Agriculture, Environment, and Employment, local government, user groups and civil society. 
    Rather than merely acting as a talking shop, the CLIPs should take the initiative in tackling pesticide problems and their causes, starting with small but concrete actions. These could include detailed studies on environmental conditions or farmworker health and safety, focusing on sectors at greatest risk. PLAGSALUD encourages CLIPs to train local health professionals, pesticide retailers and end-users and to play a high profile role in the local media. Information should be shared across institutions and the local health system must improve its poisoning data collection, working with all health staff and those compiling statistics.

Source: Diagnostico de la exposicion y efectos del uso de los plaguicidas en Madriz, Serie Diagnosticos 3, Proyecto Plagsalud, OPS/OMS-DANIDA, Managua, Nicaragua, 2000, 50 pp.

For more information contact PLAGSALUD on: opsoms@ops.org.ni and http://www.ops.org.ni/

[This article first appeared in Pesticides News No.51, March 2001, p5-7]

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