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Spreading toxic substances is not the solution!
Spreading toxic substances is not the solution!
Every year, Italy uses OVER 50% of all insecticides consumed in the European Union [1], adding those used in agriculture and those in urban areas. In Italian cities, disinfestation against mosquitoes, in particular against the tiger mosquito (Aedes albopictus), is a frenetic practice. From spring to autumn, thousands of tons of substances officially declared as seriously toxic are dispersed in streets, homes, gardens, parks, schools, hospitals, and other public places. Municipal ordinances justify the use of these insecticides by citing the tiger mosquito as a potential vector of diseases such as Chikungunya and Dengue, and Culex pipiens as a vector of the West Nile virus. However, scientific studies carried out by bodies such as European Consumer and WWF demonstrate that it is actually "psychological terrorism" [1].
The widespread panic regarding the tiger mosquito is therefore unfounded, and the use of toxic substances in the environment, which cause tangible damage to both human health and biodiversity, is even more unjustified. These chemicals, accumulating in the environment, can have unpredictable synergistic chronic effects. They can cause serious damage, such as genetic alterations, endocrine disruption, and accumulation in living organisms and food chains. This damage is particularly unacceptable if we consider that only a small part of mosquitoes are actually eliminated through spraying, while their population continues to reproduce uncontrollably. In fact, new generations of mosquitoes survive and develop greater resistance to chemicals, leading to the birth of increasingly immune strains and increasingly numerous populations. This cycle inevitably leads to the creation of increasingly powerful and dangerous chemicals in an attempt to combat them, without obtaining effective results [1].
Pesticides are linked to serious pathologies such as neurodegenerative diseases, childhood cancers, malformations and infertility [2].
The president of WWF Rome, Raniero Maggini, underlined that the substances used in mosquito disinfestations, often indicated as "particularly dangerous", represent a serious threat to human and animal health and to the urban ecosystem [2]. Despite this, these disinfestations continue to be recommended and used by both public and private bodies, fueling misinformation that promotes the use of chemical solutions. The current rules allow the use of highly toxic substances in residential areas, while funds should be invested in training citizens on biological and larvicidal control, the only truly effective one. This solution to counteract the proliferation of mosquitoes, in particular the tiger mosquito, is prevention through biological anti-larval treatments. Correct information and the adoption of natural methods are essential to solve the problem at its root.
Contradictions emerge from the comparison with other Member States, where there are no anti-mosquito disinfestation activities comparable to the Italian ones. Furthermore, pesticides, which are banned in agriculture, are allowed in urban settings, often with minimal precautions. Another serious problem is the destruction of mosquitoes' natural predators, such as bats, geckos and dragonflies, which paradoxically favors the proliferation of mosquitoes [1].
Impact on ecosystems and living beings of synthetic substances used in mosquito prophylaxis
Impact on ecosystems and living beings of synthetic substances used in mosquito prophylaxis
Impatto_sugli_ecosistemi_e_sugli_esseri.pdfCarlo Modonesi (Zoologo, Università degli Studi di Parma, Gruppo Pesticidi ISDE), Celestino Panizza (Medico del lavoro, Gruppo Pesticidi ISDE)
The by-products of industrial plants, incinerators, vehicular traffic and energy plants are among the main sources of chemical pollution in the environment. However, there is another category of chemical pollutants, known as "pesticides," that are deliberately introduced into the environment due to their toxicological properties.
The ideal pesticide should be selectively toxic only to the target organism, the species you want to control or eliminate for economic or other reasons, and simultaneously harmless to humans and all other organisms.
However, very few synthetic compounds, even those designed and developed with great precision such as pesticides, manage to achieve a level of selectivity that guarantees an action limited to a single species. This reality suggests a common sense principle: whenever planning a pest control program in any environment involving the use of toxic substances, it is essential to carry out a thorough assessment of the health risks and associated environmental costs. Without such assessment, risks and costs tend to be treated as “external,” a convenient but problematic label that shifts the social harm caused by private activities onto the community [2].
This short essay offers a review of the available specialist literature on the health effects of pyrethroid pesticides.
PYRETROIDS: Between Environmental Quality and Public Health - Toxicological Aspects [2]
The literature on human and animal health risks deriving from pyrethroids documents a series of acute exposure reactions, including: Dyspnea, respiratory tract irritation, bronchospasm, nausea, tremors, vomiting, drooling syndrome, increased body temperature, choreoatheosis , skin reactions. Pyrethroids can also cause local paresthesias and allergies by inhalation or skin contact (Ujváry, 2010; Koureas et al., 2012).
The best-known long-term effects, confirmed by epidemiological and animal studies, include carcinogenesis, neurobehavioral pathologies, neurodevelopmental disorders, reproductive syndromes, immunological damage, and endocrine disruption (Shafer et al., 2005). Among the most used pyrethroids is cypermethrin (CYP), widely used in agriculture and in the domestic context. Cypermethrin is a major contaminant in aquatic systems, where it has shown cytotoxicity and immunotoxicity in Zebrafish embryos and other species (Saha et al., 2009; Jin et al., 2011a).
Experiments and Studies
Although often described as low-grade mammalian toxicity, studies in rodents have shown that CYP exposure can significantly alter the oxidative function of liver enzymes and destabilize the endocrine system in adolescents. Other studies indicate that perinatal intake of permethrin can affect the development of the central nervous system, with degenerative effects similar to those of Parkinson's syndrome (Jin et al., 2011b). Furthermore, in vivo studies on rodents have shown that ingestion of permethrin can compromise the immune response of T lymphocytes, even at doses lower than lethal ones (Cox, 1998).
In terms of carcinogenic risk, cases of benign lung tumors in mice and liver tumors in rats have been reported following exposure to pyrethroids (Ishmael et al., 1988; Hakoi et al., 1992). Studies have shown liver and lung carcinogenicity, genotoxicity for lymphocytes and inhibition of intercellular communication (Hakoi et al., 1992; Gabbianelli et al., 2004; Tateno et al., 1993).
In pets, particularly dogs and cats, pyrethroids can cause acute intoxication, with cats showing greater sensitivity than dogs. The most common symptoms in cats include convulsions, tremors, fasciculations and hyperthermia, while in dogs convulsions, hypersalivation and ataxia are observed. Studies on cases of pyrethroid intoxication in cats have reported central neuropathic syndromes in a significant percentage of subjects (Whittem, 1995; Anadón et al., 2009).
Regarding endocrine disruption, some pyrethroids appear to disrupt the endocrine system, with possible negative consequences on health and reproduction. Combined studies in animals and humans suggest that pyrethroids may adversely affect nervous development and reproduction (Hanke et al., 2004; Shafer et al., 2005; Koureas et al., 2012).
A Canadian study associated exposure to pyrethroids with neurobehavioral problems in children, and other investigations have highlighted genotoxic effects and interference with the human reproductive system (Oulhote, 2013; Meeker et al., 2008). Recent studies have also documented a correlation between urinary metabolites of pyrethroids and hormonal alterations in individuals not professionally exposed (Han, 2008). It is observed that children represent the segment of the population at greatest risk of exposure to pyrethroids, due to their low body weight and less developed detoxification mechanisms. This makes them particularly vulnerable to the neurotoxic and endocrine effects of these substances.
Pyrethroids and Cancer in Humans [2]
The classification of pyrethroids in relation to their carcinogenic potential has generated some ambiguity in the scientific community. According to IARC (International Agency for Research on Cancer) monograph 53, the compounds deltamethrin, permethrin and fenvalerate are classified in group 3. This group includes substances for which evidence of carcinogenicity is inadequate for humans and animals, indicating that there is insufficient evidence to define them as carcinogenic.
On the other hand, the US EPA (Environmental Protection Agency) has adopted a more cautious approach, classifying pyrethroids as "likely carcinogenic to humans" (EPA, 2007). This categorization reflects concern about carcinogenic potential, although the evidence is inconclusive.
Some recent studies, such as the one conducted by Rusiekj (2009) as part of the Agriculture Health Study, have attempted to clarify this uncertainty. This study found no significant association between permethrin exposure and most cancers in workers who apply it. However, there was a significantly increased risk of multiple myeloma among those who had prolonged or intense exposure to permethrin. The risk of multiple myeloma in these categories of workers was significantly elevated, with a hazard ratio (RR) of 5.72 (95% CI, 2.76-11.87) for those with prolonged exposure and an RR of 5.01 (95% CI, 2.41-10.42) for those who had more intense exposure.
Other studies have suggested possible associations between exposure to pyrethroids and the onset of leukemia in children. An investigation conducted by Ding (2010) observed a dose-response relationship in leukemic children aged 0-14 years. In this study, as the concentration of urinary pyrethroid metabolites increased, the risk of acute lymphocytic leukemia increased significantly, with an Odds Ratio (OR) of 2.75 (95% CI, 1.43-5.29) in the quartile with the highest concentration of metabolites.
A case-control study conducted in Brazil (Ferreira, 2013) further examined the link between exposure to pyrethroids during pregnancy and the onset of leukemia in children younger than 2 years of age. This study highlighted a positive association between exposure to pyrethroids, particularly permethrin, and the onset of acute lymphocytic leukemia and acute myeloid leukemia in children, with a particularly high risk of acute myeloid leukemia in children aged 0-11 months (OR = 7.28; 95% CI: 2.60, 20.38).
These studies indicate that, although the evidence is not definitive, there are real concerns about the carcinogenic potential of pyrethroids, especially in vulnerable populations such as children and workers with high exposure.
Security [2]
The environmental and health safety of synthetic pyrethroids is far from guaranteed. The widespread use of these compounds in various contexts, from mosquito disinfestation in urban areas to insect management in domestic, agricultural and industrial settings, raises significant concerns. These are further aggravated by the fact that these substances are often marketed and used without providing adequate information to the exposed population. This is particularly worrying in public places frequented by people of all ages and health conditions, such as schools, parks, sports centres, as well as in private spaces such as gardens and workplaces.
The absence of adequate preventive and precautionary measures risks making exposure to pyrethroids almost omnipresent, especially in certain seasons of the year, such as during condominium disinfestation campaigns. This poses a significant and often unaware risk to much of the population, with particularly serious implications for vulnerable groups, such as children and pregnant women.
In conclusion, there seems to be a lack of clear will to integrate prevention and precautionary principles into decision-making processes regarding the use of these pesticides. This deficit not only puts environmental quality and public health at risk, but also compromises social participation in land and resource management choices, which should be oriented towards collective well-being.
Insecticide poisoning
Insecticide poisoning
Many insecticides cause poisoning if they are ingested, inhaled, or absorbed through the skin. Symptoms of poisoning can range from watery eyes, coughing and heart problems to difficulty breathing. The diagnosis of insecticide poisoning is based on symptoms, blood tests, and a description of the circumstances under which the exposure occurred. There are effective drugs for the treatment of severe forms of insecticide poisoning [3].
Serious poisonings are often caused by organophosphorus and carbamate insecticides, particularly in cases of accidental poisoning in the workplace. Organophosphoruses include substances such as malathione, parathione and sarin, while carbamates include compounds such as aldicarb and carbaryl [3].
Symptoms of organophosphorus and carbamate poisoning may include:
Tearing
Blurred vision
Excessive salivation
Sweating
Cough
Vomit
Convulsions
Low blood pressure
Irregular heart rate
These symptoms can last hours or days, while muscle weakness can persist for weeks. Pyrethrins, on the other hand, can cause sneezing, watery eyes and coughing, with serious symptoms only rarely.
Diagnosis
To diagnose insecticide poisoning, the history of exposure and characteristic symptoms are considered, supported by blood tests and response to treatment with atropine. Treatment includes removing contaminated clothing, washing the skin, and supporting respiratory and cardiac functions. Atropine, administered intravenously, can relieve most symptoms caused by organophosphates. Pralidoxime, administered intravenously, can accelerate the recovery of nerve function. However, in cases of carbamate poisoning, pralidoxime is not always effective. Symptoms caused by pyrethrins generally resolve without the need for treatment [3].
Bibliography
[1] WWF, I. D. (2022). wwf. Obtenido de http://wwf. panda. org/es/acerca.
[2] Bellucci, V., & Carlo, J. Impatto sugli ecosistemi e sugli esseri viventi delle sostanze sintetiche utilizzate nella profilassi antizanzara.
[3] Gerald F. O’Malley, DO, Grand Strand Regional Medical Center; Rika O’Malley, MD, Grand Strand Medical Center (2022), https://www.msdmanuals.com/it-it/casa/lesioni-e-avvelenamento/avvelenamento/avvelenamento-da-insetticidi#Trattamento_v28488735_it
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