The present study revealed that the ratio of pesticide-related deaths to all poisonings was 41.9%. Similar ratios were observed in other agricultural producing countries. In China, for instance, Qian reviewed the records of 218 poisoning deaths from the Tongji Center for Medicolegal Expertise in Hubei, from 1999 to 2008 (Qian et al. 2009). He reported that 37.6% of toxic deaths were caused by pesticides. These cases are fewer in occidental countries. In fact, in the USA, pesticides were incriminated only in 3.47% of the cases of poisoning in 2018 (Gummin et al. 2019).
In the present study, the mean age of fatal pesticide-poisoning victims was 27.46 years. Kahraman et al. evaluated pesticide poisonings in a University Hospital in Turkey, from June 1, 1993, to June 31, 2007, and they reported that the mean age was 34.1 years (Kahraman et al. 2008). In the study of Derkaoui et al., reviewing 28 patients intoxicated with organophosphorus pesticides in Fès, Morocco, for 7 years between January 2003 and December 2010, the mean age was also young 24.5 years (Derkaoui et al. 2011). In fact, this period of age is associated with big social pressure for young adults leading to suicide by pesticide poisoning (Turecki et al. 2019). We found that 21% of intoxication victims were children aged under 18 years. Similarly, Maria et al. reported that 6.6% of the cases of poisoning in the state of Mato Grosso do Sul, Brazil, from 1992 to 2002, concerned children aged between 5 and 14 years (Maria et al. 2006). Pesticide poisoning among children is frequently accidental. In this period of age, children tend to explore the outside world and they interact with objects by putting them in their mouths (Gooch et al. 2016).
A female predominance was observed in our study. Derkaoui et al. reported a similar rate of female victims (67%) in Morocco (Derkaoui et al. 2011). This may be explained by the fragile attitude of women facing conflicts. It is also known that women hesitate and choose uncertain modalities of suicide such as pesticide poisoning compared to men who prefer more radical methods such as hanging (González et al. 2015).
As is the case in many studies, we have noticed that the majority of pesticide poisoning cases happened in rural areas (Maria et al. 2006; Kahraman et al. 2008; Qian et al. 2009; Derkaoui et al. 2011; Idiz et al. 2012; Wang et al. 2019; Gummin et al. 2019). This is mainly because pesticides are frequently used in agriculture. Furthermore, these regions are distant from medical facilities which make access to urgent medical assistance difficult. The low socioeconomic position and the poor educational level are also major risk factors (Idiz et al. 2013). In our study, 13.8% of the victims had a psychiatric history. Many studies emphasized on the role of psychiatric disorders in triggering suicide (Maria et al. 2006; Kahraman et al. 2008; Qian et al. 2009; Derkaoui et al. 2011; Idiz et al. 2012; Wang et al. 2019; Gummin et al. 2019).
Four victims were found in a state of coma. Coma is one of the most frequent signs of chloralose intoxication and it is generally profound (Richardson et al. 2019). Five percent of the victims exhibited respiratory symptoms. This is due to the bronchoconstriction and hypersecretion of mucus in the bronchi consequent to the muscarinic effect. OP may also, induce the paralysis of peripheral respiratory muscles when they interact with the nicotinic receptors and depress the central nervous respiratory centers (Nordgren and Bailey 2016).
Bluish discoloration of the lips and the limbs resulting from severe hypoxia was observed in all the victims. These signs are nonspecific of pesticide poisoning deaths and may be found in natural deaths. In our study, the most frequent signs discovered during autopsies were pulmonary edema and multiorgan congestion consequent to cardiac failure. Four victims had histological signs of acute pancreatitis. Yoshida et al. also reported cases of pancreatitis consequent to OP intoxication (Yoshida et al. 2015). Sixty-nine victims had abundant mucus in the bronchi. This is explained by the hyperactivity of the parasympathetic system induced by the intoxication (Mostafalou and Abdollahi 2017).
In our study, the most incriminated products were carbamate insecticides in 50% of the cases followed by OP insecticides in 31.5%. Idiz et al. reviewed the deaths from pesticide poisoning occurring in Izmir, Turkey, from 2006 to 2009, and found that similar to our study carbamate insecticides were the major cause of death (Idiz et al. 2012). On the contrary, in the study of Wang et al. concerning pesticide poisoning in Jiangsu Province, China, from 2007 to 2016, the number of poisonings by organophosphate pesticides was the highest (18,548), accounting for 60.2% of all cases (Wang et al. 2019). Carbamates and organophosphates are anticholinesterase agents. Deaths are related essentially to respiratory disorders (Mostafalou and Abdollahi 2017). We found that only two victims were intoxicated with OC insecticides. This is due to the official ban of these products from commercialization (Strategic Approach to International Chemical Management (SAICM) Regional SAICM Implementation Report, 2012). Nevertheless, the Pesticide Action Network report estimates that an enormous stock of absolute OC products remains undestroyed explaining the occurrence of sporadic cases of intoxication with such compounds (Strategic Approach to International Chemical Management (SAICM) Regional SAICM Implementation Report, 2012). Eighteen victims in our study were poisoned with an alpha chloralose rodenticide. In the literature, few cases of chloralose poisoning have been reported (Maria et al. 2006; Kahraman et al. 2008; Qian et al. 2009; Derkaoui et al. 2011; Idiz et al. 2012; Wang et al. 2019; Gummin et al. 2019). Issifou analyzed 92 cases of fatal pesticide poisoning in the region of Sfax, south Tunisia, and found that chloralose poisoning represented 10.9% of the cases of pesticide intoxication deaths (Issifou 2004). The toxic dose of chloralose is 1 g among adults and 20 mg/kg among infants (Mostafalou and Abdollahi 2017). Deaths are essentially due to neurological disorders leading to coma (Mostafalou and Abdollahi 2017).
In the present study, suicide (n = 120, 92%) was the most common manner of death followed by accidents (n = 8, 6.1%). In a previous study by Idiz et al, suicide was also the major method of death (43.8%) (Idiz et al. 2012). In China, however, a retrospective study carried out in the Forensic Department of Tongi showed that poisoning was essentially accidental (Qian et al. 2009). One of the male victims in the current study committed suicide after being sexually assaulted. It is known that sexual assaults increase the risk of suicide (Mathilde et al., 2013). In our study, two infants aged 6 and 8 months were poisoned by their mothers. In the literature, criminal pesticide-poisoning cases are also rare. Helena et al., for instance, reported that homicide with pesticide poisoning represented only 1% of cases of toxic deaths (Helena et al. 2004).
The modalities of the use of pesticides are fixed by the WHO and the specific legislation of each country. In fact, the WHO defines each pesticide by its name, a number of the WHO standard, and the concentration of the active ingredient in its formula (World Health Organization and Food and Agriculture Organization of the United Nations, 2016). Class Ia includes extremely hazardous pesticides while class III is composed of slightly hazardous compounds. In Tunisia, law number 1961-39 promulgated on the 7th of July 1961, stipulates that pesticides cannot be commercialized without getting an official authorization from the authorities (Official Printing Office of The Republic of Tunisia 1961). Furthermore, this same law prohibits the conservation and the marketing of these products in facilities near food products. The 7th article of this same law also prohibits selling pesticides to children aged under 16 years. Moreover, law number 2010-2973 promulgated on the 15th of November 2010, states that in agriculture, pesticides must be used only by individuals with prior experience in pesticide management practices (Official Printing Office of The Republic of Tunisia 2010). It also insists that the nature of pesticides and the precautions for use must be clearly mentioned on the product package.
The restriction of the availability of pesticides and the promulgation of more strict legislation is known to be the most efficient preventive measures (World Health Organization and Food and Agriculture Organization of the United Nations, 2016) (Flemming et al. 2003). For instance, in the USA, the instauration of rigorous legislation concerning pesticide marketing and use reduced intoxication accidents significantly (Donley 2019). In the third world, the rigorous application of regulatory measures has also led to a significant decrease in pesticide-related mortality in several countries (Flemming et al. 2003). For example, the Department of Agriculture of Sri Lanka banned the use of fenthion and dimethoate, two class II pesticides, from June 2003. The comparison of the data 1 year before the ban (01 July 2002 until 30 June 2003) with 2 years after the ban (01 July 2004 until 30 June 2006) showed that hospital admissions for dimethoate and fenthion poisoning fell by 43%. The pesticide case fatality fell from 14.4 to 9.0% (Michael et al. 2012). Raising public awareness about the dangers of pesticides and the use of less toxic, equally effective alternatives were also factors contributing to the decrease in intoxication cases. In Tunisia, the prevention of pesticide poisoning started by the eradication of obsolete stocks of pesticides since 2005 as a part of the African Program on Obsolete Stocks of Pesticides (PASP-Tunisia program) (Strategic Approach to International Chemical Management (SAICM) Regional SAICM Implementation Report, 2012). This program aimed to reinforce the capacity of Tunisian institutions for rational management of chemicals, in general, and pesticides, in particular.
In Tunisia, there are two anti-poison centers, one in Tunis and the other in Sousse. The anti-poison centers (CAP) offer prevention and teaching activities. They provide appropriate toxicological information through constantly updated documentation, including the composition of the commercial products, their toxicity and the therapy to be implemented for each product concerned. These centers need to be developed nationally and regionally.
Globally, the International Code of Conduct on the Distribution and Use of Pesticides was enacted by the Food and Agriculture Organization of the United Nations (World Health Organization and Food and Agriculture Organization of the United Nations, 2016). It attempts to rationalize the use of pesticides and reduce the health and environmental risks associated with them. Its stated aim is to establish voluntary standards of conduct for all public and private entities engaged in or associated with the distribution and use of pesticides. The new version of the Code of Conduct adapts a “life-cycle” concept to address all stages from the development of products to the final disposal of containers (World Health Organization and Food and Agriculture Organization of the United Nations, 2016).