Health risks of using mothballs in Greater Accra, Ghana

Authors


Corresponding Author Sari Soghoian, NYC Poison Center, 455 First Avenue, Room 123, New York, NY 10016, USA. Tel.: +1 718 501 7104; Fax: +1 212 447 8223; E-mail: sarisoghoian@yahoo.com

Abstract

Objective  Internal use of ‘camphor’ is a potential public health concern in Accra. We sought to identify the toxins being sold as mothballs in Greater Accra and use this information to help educate both clinicians and the public.

Methods  Mothballs are commonly sold by street and marketplace vendors in unmarked cling film-wrapped packs. Fifteen small packs of mothballs were purchased from random vendors in three major markets and six roadside stands in Greater Accra. All samples were subjected to the float test; one sample was confirmed by gas chromatography/mass spectroscopy.

Results  All samples sank in tap water but floated in a saturated salt solution, consistent with naphthalene. The analysed sample was identified as naphthalene.

Conclusion  Naphthalene was most likely the primary ingredient in all the mothballs purchased for the study. Naphthalene is poorly soluble in water, and ‘camphor water’ is unlikely to cause harm. However, ideas about the efficacy of ‘camphor’ as a purification tool may lead to therapeutic misuse by analogy. A high prevalence of G6PD in the Ghanaian population may increase the risk of toxic haematologic effects from ingestion of mothballs. Mothballs known in Greater Accra as ‘camphor’ are likely to be predominantly naphthalene. A public awareness campaign about the health risks of mothball ingestion is planned.

Abstract

Objectif:  L’usage du “camphor”à l’intérieur est une préoccupation de santé publique potentielle à Accra. Nous avons cherchéà identifier les substances vendues sous forme de boules antimites dans la l’agglomération élargie d’Accra et utiliser cette information pour aider àéduquer les cliniciens et le public.

Méthodes:  Les boules antimites sont couramment vendues par les vendeurs de rue et sur le marché dans des sachets plastiques sans inscription. 15 petits sachets de boules antimites ont été achetés auprès des vendeurs choisis au hasard dans trois grands marchés et 6 étalages routiers dans l’agglomération d’Accra. Tous les échantillons ont été soumis au test de flottaison; un échantillon a été confirmé par chromatographie gazeuse couplée à la spectroscopie de masse.

Résultats:  Tous les échantillons ont coulé dans l’eau du robinet, mais flottaient dans une solution saturée en sel, en conformité avec le naphtalène. L’échantillon analysé a été identifié comme étant du naphtalène.

Conclusion:  Le naphtalène était probablement le principal ingrédient dans toutes les boules antimites achetées pour l’étude. Le naphtalène est peu soluble dans l’eau et “l’eau de camphre” est peu susceptible de causer des dommages. Cependant, les idées reçues sur l’efficacité du “camphor” comme substance de purification peuvent conduire à une mauvaise utilisation thérapeutique par analogie. Une prévalence élevée de la G6PD dans la population ghanéenne peut augmenter le risque d’effets toxiques hématologiques liés à l’ingestion de boules antimites. Les boules antimites connue à Accra sous le nom de “camphor” sont susceptibles d’être composées majoritairement de naphtalène. Une campagne de sensibilisation du public sur les risques pour la santé de l’ingestion de boules antimites est prévue.

Abstract

Objetivo:  El uso interno del “alcanfor” es un posible riesgo de salud pública en Accra. Hemos buscado identificar las toxinas que se venden como bolas antipolillas en Gran Accra, utilizado esta información para ayudar en la educación tanto de clínicos como del público.

Métodos:  Las bolas antipolilla se venden comúnmente en las calles y los mercados, envueltas en papel y sin etiquetar. Se compraron 15 paquetes pequeños de bolas antipolilla a vendedores elegidos al azar en 3 de los principales mercados y 6 puestos de la carretera de Gran Accra. Todas las muestras se sometieron a la prueba de flotación; una muestra se confirmó mediante cromatografía de gases.

Resultados:  Todas las muestras se hundieron en agua corriente pero flotaron en una solución saturada con sal, resultado consistente con la naftalina. La muestra analizada se identificó como naftalina.

Conclusión:  La naftalina es probablemente el principal ingrediente de las bolas antipolillas compradas para el estudio. La naftalina es poco soluble en el agua, y el agua de alcanfor es improbable que haga daño. Sin embargo, las ideas sobre la eficacia del alcanfor como purificador podrían, por analogía, llevar a un mal uso terapéutico. Una alta prevalencia de G6PD en la población de Ghana podría aumentar el riesgo de efectos hematológicos tóxicos tras la ingestión de bolas antipolillas. Las bolas antipolillas conocidas en Gran Accra como “camphor” parecen ser naftalina. Se está planeando una campaña de educación pública sobre los riesgos para la salud de ingerir bolas antipolilla.

Introduction

In a prior study evaluating the risk factors for poisoning in Greater Accra, we identified the internal use of ‘camphor’ as a potential public health concern (Soghoian et al. 2009). In-depth interviews with 104 lay persons and 26 health care providers were conducted to assess patterns of exposure and perceptions of the potential for harm associated with various household and other poisons. Twenty-four per cent of the community (lay person) interviewees in the survey reported using ‘camphor’ (mothballs) routinely to purify water for drinking and bathing. Several people gave specific recipes for making this ‘camphor water’, which they described as having a pleasing smell as well as internal cleansing abilities when used as a wash, gargle, drink or as an enema. In addition, two of the physicians who were interviewed reported that they had cared for patients with haemolytic anaemia after ingestion of one or more whole ‘camphor’ mothballs to self-treat stomach ache, measles and diarrhoea. As haemolysis is uncharacteristic of camphor ingestion, we sought to identify the toxins being sold as mothballs in Greater Accra and to use this information to help educate both clinicians and the public about the specific health risks of internal mothball usage in Greater Accra.

Methods

Mothballs are sold in both formal and informal sector markets in Greater Accra. Whereas in formal sector markets mothballs are typically sold in labelled packs, in informal markets they are sold in unlabelled home-made cling film-wrapped packs containing two or three mothballs each. For this study, 15 small unlabelled saran-wrapped packages of mothballs were purchased from randomly selected informal sector vendors in various locations throughout Greater Accra. Nine of these packs were purchased in three of the largest open-air markets in the city, and six packs were purchased at roadside stands along major thoroughfares in central Accra. A random selection of stores in six neighbourhoods was also surveyed for the sale of commercially packaged mothballs. Contents on the labels were noted. All brands listed naphthalene as the single ingredient, and a single package was purchased.

All samples were then subjected to the float test, which rapidly distinguishes camphor, naphthalene and paradichlorobenzene (Koyama et al. 1991). The chemical identity of one mothball sample was confirmed by the New York City Department of Health Laboratory using gas chromatography/mass spectrometry.

Results

All commercially packaged mothballs were labelled as containing naphthalene. We did not find any commercially packaged mothballs that were labelled ‘camphor’ or ‘paradichlorobenzene’. All samples of mothballs, including the 15 unlabelled samples and one commercial sample, sank in a cup of tap water but floated in a saturated salt solution, consistent with the behaviour of naphthalene. The laboratory-analysed sample was identified as naphthalene (see Figure 1).

Figure 1.

 Chemical identity of mothball sample purchased in Accra, Ghana.

Discussion

The goal of this study was to understand the chemical identity and risks of toxicity associated with the usage of mothballs in Greater Accra. Mothballs are typically made of camphor, naphthalene or paradichlorobenzene (PDB). Camphor mothballs are still sold in many parts of the world today. However, the commercial sale of concentrated camphor-containing products is restricted in the European Union, United States, Canada and Australia because of its neurotoxicity and ability to rapidly cause seizures after acute exposure. Most mothballs sold in these countries contain PDB, which is rarely associated with any toxic effects although haemolytic anaemia has been reported in association with acute ingestion (Sillery et al. 2009) and neurologic toxicity is reported after chronic, repeated ingestion (Avila et al. 2006). Naphthalene has an intermediate toxic profile and is also widely manufactured and sold as mothballs, insect-repellent powder or flakes. The European Union banned the use of naphthalene as an ingredient in products intended for home use 2008, but in Australia and the United States only the states of Queensland, Australia and California, USA, have any legal policies restricting the sale of naphthalene. Naphthalene products must be registered and labelled with proper use directions in the rest of the United States (Lim 2006).

Although mothballs are colloquially referred to as ‘camphor’ in Ghana, we suspected that they might not contain camphor. In fact, we were unable to find any mothballs during our survey whose behaviour was consistent with camphor using the float test. All of the mothballs purchased for the study contained naphthalene instead. Naphthalene is a waxy, opaque, white-coloured solid that is extremely volatile at room temperatures and has a distinctive odour. It is highly lipophilic and can be absorbed in the body by many routes; toxic effects have occurred in humans following dermal, oral or inhalation exposure. However, as naphthalene is poorly soluble in aqueous solutions, it is unlikely that the process of soaking mothballs in water to make ‘camphor water’ would result in a high enough concentration of naphthalene to cause significant toxicity in humans, except possibly in patients predisposed to haemolysis such as those with severe G6PD deficiency.

The primary toxicologic risk associated with naphthalene exposure is haematologic (Kuffner 2006). Naphthalene itself is non-toxic, but the oxidative metabolites alpha- and beta-naphthol are potent oxidant stressors that may cause methemoglobinemia and/or haemolysis, potentially leading to anaemia, hypoxia, jaundice, shock, acute renal failure and even death. The risks associated with exposure to oxidant compounds are higher in persons with susceptible variants of G6PD deficiency. This condition is relatively common in West Africa, where rates of G6PD deficiency are estimated at 10–20% of the population. In a recent study that examined G6PD prevalence in Ghana, the rate was about 10% in a mixed sample of the population but as high as 19% in a sample of Ga people (the Ga are a coastal tribe making up a large part of the population in the Greater Accra region in Ghana) (Clark et al. 2009). A high prevalence of G6PD deficiency in the Ghanaian population may therefore increase the risk of toxic effects from ingestion of mothballs or other naphthalene-containing products.

The mothball preparations described by the lay persons we interviewed in Accra appear to be relatively safe for internal use; however, the misattribution of health benefits is worrying. If water infused with mothballs is considered a purifying substance, then by extension the mothballs themselves may be assumed to have an even more potent ability to cleanse the body. This was the logic used by the two patients who ingested mothballs before presenting to hospital with haemolytic anaemia, as reported by physicians we interviewed during our prior study of poisoning risks in Greater Accra. One patient had described ingesting several mothballs in an attempt to cure measles (to ‘make the rash come out’), while the other stated he had ingested ten mothballs to cleanse his bowels as a cure for stomach ache. As these cases demonstrate, an analogy between insect-repellent properties and the ability to rid the body of disease is a potentially dangerous equation.

The use of naphthalene for body care and as a home remedy has previously been reported in Nigeria (Familusi & Dawodu 1985; Owa et al. 1993). A survey of 450 women of child-bearing age found that above 75% used naphthalene in the care of their infants (Familusi & Dawodu 1985). Mostly, a naphthalene powder or naphthalene-containing flakes were used as a preservative or insect repellent applied to the clothes after washing. However, six mothers in that study also reported mixing the powder into hair or body lotions, and one family used it to make a home remedy for cough. Self-reported use of naphthalene for infant care was not associated with an increased incidence of neonatal jaundice in this cohort but was significantly correlated with severe neonatal jaundice, defined as a need for exchange transfusion (Familusi & Dawodu 1985).

Because the float test is non-specific and only one sample was analysed using gas chromatography mass spectrometry, it is possible that other chemicals may have been present in some of the mothballs included in the study. However, our results strongly suggest that mothballs known in Greater Accra as ‘camphor’ today are probably composed predominantly of naphthalene.

Conclusions

Ideas about the efficacy of ‘camphor’ as a purification tool may lead to therapeutic misuse by analogy, and the high prevalence of G6PD in the Ghanaian population may increase the risk of toxic haematologic effects from ingestion of mothballs. More work is needed to understand the socio-cultural significance of ‘camphor’ usage in Ghana, in order to develop appropriate messaging. Information about the active ingredient and specific risks of mothball use should also be included in the training of public health workers and clinicians in Ghana.

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