Pesticides and Children’s Health: the Vulnerability Pendulum

Introduction

The International Labour Organisation (ILO) defines a ‘child’ as a human being below 18 years of age, and ‘child labour’ as work that deprives children of their childhood, their potential and dignity, and that is harmful to physical and mental development. There were some 264 million children aged 5-17 in economic activity in the world in the year 2012. About one-tenth of the total child population i.e. 168 million children aged 5-17 years—was involved in child labour in 2012 (and was 215 million in 2008). Hazardous work which is the worst form of child labour accounts for almost half of all child labourers. The largest number of children in hazardous work is found in the Asia-Pacific (33.9 million), then Sub-Saharan Africa (28.8 million), Latin America and Caribbean (9.6 million), and Middle East and North Africa regions (5.2 million). In relative terms, Sub-Saharan Africa region has the highest incidence of children in hazardous work, with one in ten children involved. In terms of sectors, the highest percentage of child labour (58.6%) was concentrated in agriculture, services (32.3%), industry (7.2%), and 1.9% in non-classified sector (ILO, 2012). A study amongst small holder farmers in Pallisa and Wakiso Districts in Uganda also revealed that 78.7% of farm labour is supplied by family members, of which children are usually a majority component of a family composition (UNACOH, 2011). The foregoing predisposes children to among others, potent chemicals (pesticides) used by the farming fraternity to curtail pest infestations and disease infections.

The United Nations Food and Agriculture Organization (FAO) defines a “pesticide” as, “any substance, or mixture of substances of chemical or biological ingredients intended for repelling, destroying or controlling any pest, or regulating plant growth. Pesticides are often referred to by other names such as agrochemicals, or crop protection/plant protection products (FAO, 2011). Pesticides are majorly synthetic manufactured chemicals that do not exist naturally. Therefore, there are often no protective mechanisms in the human body and often no natural organisms which have evolved to break down these poisons into less harmful substances. As a result, many pesticides are also persistent in the human body, soils and water, and accumulate in food chains and the environment (International Code of Conduct on Pesticide Management, 2013). Pesticides impair the functioning of biological processes essential for life, such as the nervous and reproductive systems. Very often, these processes are similar among different organisms, whether humans or insects. Exposure to pesticides can result in acute poisoning and/or longer-term chronic health problems.

Children’s vulnerability

Children’s vulnerability to pesticide exposure is proliferated by factors hereunder; (a) because of their physical stature, children live and play closer to the ground where many contaminants are found; (b) behaviours such as oral exploratory, hand-mouth, pica, poor hand washing, and curiosity in exploration; (c) they are less able to assess risks as their judgment is not fully developed; (d) they have a higher metabolic rate thus breathe more air, drink more water, and eat more food (e.g In the first 6 months of life, children drink seven times as much water per kilogram of weight than does an adult, an infant's respiratory rate is more than twice that of an adult's, from 1 to 5 years of age, children consume three to four times more food per kilogram of weight than do adults). These result in greater exposures per kilogram of body weight to any contaminants in the air, water, or food, compared with adults; (e) they have an increased surface area-to-body mass ratio resulting in an increased risk of dermal exposure and absorption; (f) immobility of young children which means they have to rely on adults to remove them from hazardous exposure situations; (g) because their metabolic systems are still developing, children’s ability to detoxify and expel toxins is limited.

It’s worth noting that a child’s vulnerability to pesticide exposure can be exacerbated by other factors such as the parent/caretaker’s occupation and socio-economic attributes like poverty. For example (i) a farmer’s or fumigator’s child stands a higher risk of getting exposed to pesticides; (ii) a poor housing facility is a predisposing factor to pesticide exposure due to indiscriminate storage and non-gazetted children’s play or sleeping areas.

Children’s exposure

Children’s exposure to pesticides may be intense but over a short period of time (acute exposure) and/or low-dose but continuous/long-term (chronic exposure). Irrespective of the type of exposure, common points of pesticide entry are the mouth (oral), nose (inhalation), skin (dermal) and eyes (ocular). In addition breast-feeding infants may be exposed to lipophilic pesticide contaminants in breast milk. Children can be exposed to pesticides anywhere along the pesticide handling cycle; from buying to disposal of containers and equipment/clothing clean up. Children’s exposure is majorly unintentional (occupational or accidental), with minimal intentional (suicidal and homicidal) cases as observed through poisoning registration forms administered by Uganda National Association of Community and Occupational Health (UNACOH) at different health facilities in east and central Uganda (UNACOH, 2014). Children’s unintentional exposure can take place during agricultural work (e.g. working/playing in fields during spraying, touching sprayed crops, being close to fields being sprayed in windy conditions), domestic work (e.g playing with family pets that have been treated for flea problems, playing in just sprayed houses/stores, washing spray clothes & equipment, re-using pesticide containers to keep food or drink, sleeping in the same room with pesticides), and sales work (e.g handling leaking containers in a shop, playing in a pesticide shop with fumes). In addition they can be exposed to pesticides through the food they eat, water they drink, on the caretaker’s back, and many more.

The impact of exposure to pesticides on human health depends on a number of factors including the pesticide’s toxicity and formulation involved, the amount, route of exposure, timing and duration of the dose. Pesticides vary in their toxicity as categorised by the World Health Organisation into Classes (Ia, Ib, II, III, IV or U) and the pesticide’s toxicity (i.e. capacity to cause harm to health) reduces from Class I to U respectively. With regard to formulation, pesticides may be in form of liquids, granules, dusts, and gas, and the effect of exposure to any of these forms will depend on the circumstances. Concerning the route of exposure, a pesticide in gas or dust form is likely to cause more harm if inhaled than when it contacts the

child’s skin. With regard to timing, it’s riskier getting exposed to pesticides when one’s skin is sweaty or moist as this quickens the absorption process due to open skin pours. This is why moist parts of the skin such as genital area, arm pits, and scalp absorb pesticides most in case of dermal exposure. Other factors include the health of the person poisoned. Malnutrition and dehydration, for example, may increase the sensitivity to pesticides.

Health effects of exposure

Children’s exposure to pesticides results into acute and/or chronic effects to their health. The short-term effects may include skin and eye irritation, nausea, head ache, coughing, paralysis, vomiting, blurred vision, dizziness, and general body weakness among others. Concerning long-term effects, satisfactory evidence from epidemiological studies on humans has not been generated (perhaps due to the research dynamics, especially duration needed to carry out such investigations). In general long-term effects of pesticide exposure in children may include; organ damage, different forms of cancer, birth defects, learning disabilities, behavioral changes, and asthma among others (FAO, 2011). In addition, different studies have produced results linking pesticide exposure to a number of health effects: for example indoor pesticides have been specifically associated with increased cancer incidence in children (Buckley et al., 2000); exposure to the herbicide 2,4-D has been found to increase the risk of circulatory and respiratory defects (Schreinemachers, 2003); pesticide exposure has also been associated with miscarriages (Bell et al., 2001b); pesticide exposure is linked to neurophysiological changes such as lowered concentration and memory, fatigue, irritability, and nervousness (Baldi et al., 2010 and Costa et al., 2008); and Whitney et al (1995) generated evidence suggestive of harm to child brain development during pregnancy following exposure to the pesticide Chlorpyrifos.

How can children’s exposure to pesticides be reduced?

A multi-stakeholder collaboration can go a long way in curbing children’s exposure to pesticides. Ministries of agriculture, labour, health and environment, plus other relevant control boards, researchers, farmers’ organisations and workers’ unions among other actors, all have an important role to play. Different measures that may be put in place to reduce children’s exposure include; (i) Development and promotion of alternative pest and pesticide management strategies; (ii) phasing out specific extremely/highly toxic pesticides; (iii) raising awareness and building capacity at different levels; (iv) collecting data on children’s exposure, so as to inform policy and sensitisation drives; (v) formulation and reinforcement of already existing national legal frameworks that aim to protect vulnerable groups like children.

Aggrey Atuhaire

aatuhaire@unacoh.org

Project Officer

PHE Project