Pros and Cons of Insect Repellents
Gail Miriam Moraru, Jerome Goddard in The Goddard Guide to Arthropods of Medical Importance, Seventh Edition, 2019
Insect repellents are chemicals that cause insects to make directed, oriented movements away from the source of the repellent. In light of disease transmission by insects and other arthropods, chemical substances that have repellent effects or interfere with biting are wonderful because they enable us to go places and do things in insect- or disease-infested areas. Undoubtedly, repellents have prevented thousands of cases of malaria, dengue fever, encephalitis, and other mosquito-borne diseases; for example, a recent study demonstrated that persons practicing two or more personal protective behaviors against mosquito bites, including repellents, reduced the risk of West Nile virus (WNV) infection by half.1 In recent years, however, concerns about the potential adverse health effects of insect repellents have increased, especially for those containing the active ingredient DEET. N,N-diethyl-3-methylbenzamide (DEET) is one of the most effective and widely used insect repellents available.2 It repels a variety of mosquitoes, chiggers, ticks, fleas, and biting flies, and an estimated 50 to 100 million people in the United States use it each year.3,4 This chapter discusses various chemical repellents, their modes of action, possible side effects, and precautions necessary to prevent adverse reactions.
Personal Protective Equipment (PPE): Practical and Theoretical Considerations
Brian J. Lukey, James A. Romano, Salem Harry in Chemical Warfare Agents, 2019
The surface area/volume ratio of the newborn is approximately three times greater than that of an adult, and the same ratio for a toddler is approximately twice that of an adult (WHO Training, 2008, slide 12). The surface area to body mass ratio is highest in the newborn period and decreases linearly through toddlerhood, childhood, and adulthood. What is really important here is to understand that the younger the patient, the greater will be the surface area/volume ratio, and the inherent problems associated with these larger ratios will also be greater. These factors couple to increase the absorptive area of the skin while decreasing the volume of distribution of a drug or toxin (Lio, n.d.). Furthermore, infant skin is more fragile than that of the adult and hence, more susceptible to penetration (i.e., cutting, both obvious cuts and unobservable microscopic cuts). Once a drug or toxic compound is absorbed, infants especially lack the drug carriage and detoxification mechanisms that are possessed by adults. Caution in applying bug repellents, such as diethyltoluamide (DEET), is strongly supported by experimental data, and these repellants should be reduced in volume (Nasr, 2010) and if possible, concentration. An obvious implication for CWAs would therefore exist. In children, there is an estimated 20% incidence of atopic dermatitis (Lio, n.d.), as compared with a single-digit incidence in adults. This further comprises the barrier function of young skin.
Agricultural Chemicals
Ana M. Giménez-Arnau, Howard I. Maibach in Contact Urticaria Syndrome, 2014
N,N- diethyl-m-toluamide (DEET) is the most commonly found active ingredient in insect repellants. Developed by the U.S. Army in the mid-1940s, it was initially tested as a pesticide on farms. Vozmediano et al. reported immunologic contact urticaria in a patient as a result of exposure to a particular insect repellant lotion containing DEET. The patient presented with edema and severe pruritic reactions to the application area. The same study also indicated that the patient did not react to other toluamides, such as N,N-diethyl-p-toluamide.[16] Negative reactions to the para isomer of DEET suggest that chemical structure dictates reactivity. Although DEET is no longer used as a pesticide, it is still of concern to those in the agricultural industry because workers may apply insect repellants to protect themselves in their working environment.
In vitro skin irritation assessment using EpiDerm™: applicability for updating toxicity information of oxybenzone and N,N-diethyl-m-toluamide
Published in Drug and Chemical Toxicology, 2020
Ji-Seok Han, Yong-Bum Kim, Heejin Park, Wan-Jung Im, Woo-Jin Kim, Younhee Kim, Joo-Yun Won, Hwa-Young Son, Byoung-Seok Lee
N,N-Diethyl-m-toluamide (diethyltoluamide, DEET) is broad-spectrum insect repellent against biting flies, biting midges, fleas, and mosquitoes, and commercially available at concentrations of 4–100% in formulations including lotions, gels, and aerosols. According to the Center for Disease and Prevention (CDC), 30–50% DEET is effective against the pathogens carried by insects; although, this depends on the times and mode of administration (CDC 2009). Regarding human exposure of DEET, there have been many reports that it can induce a variety of health effects including neurological, respiratory, gastrointestinal, and cardiovascular system. Furthermore, exposure to DEET can cause skin irritation, desquamation, and dermatitis in humans (Keith et al.2017). The American Academy of Pediatrics (AAP) has reported that 10–30% DEET is safe in children and adults when used as directed and Health Canada banned the sale of insect repellents containing over 30% DEET in a 2002 evaluation (CDC 2007, Health Canada 2009).
Zika virus in Brazil and worldwide: a narrative review
Published in Paediatrics and International Child Health, 2021
Marlos Melo Martins, Roberto De Andrade Medronho, Antônio José Ledo Alves Da Cunha
Repellents applied to the skin are a part of preventive care for arboviruses. The most used repellents are DEET (N, N-diethyl-3-methylbenzamide), IR3535 and Icaridin. The repellent effect of IR3535 is observed at concentrations above 10% and its use in a concentration of 10–30% is accepted. A concentration of 12.5% can be prescribed for children under 2 years of age. DEET-based products are allowed for children over 2 months of age in a concentration of up to 30%. Icaridin formulations containing 5–10% may be used for children over 6 months of age. Repellents should be applied to exposed areas of the body and clothing, and spray should be applied to the face or, in children, by first spraying the product on the palms and then applying it to the face or body, followed by thorough hand-washing [74].
Evaluation of surface versus total permethrin content in permethrin-treated clothing: Implications for protection against mosquitoes
Published in Pathogens and Global Health, 2022
Adam Vang, Avian V. White, Jo Anne G. Balanay, Robin Tutor Marcom, Stephanie L. Richards
Our findings agree with others [3] where a higher repellency rate was observed in mosquitoes previously exposed to permethrin in comparison to susceptible mosquitoes. While the findings of the cone assay comparing repellency rates between susceptible and exposed mosquitoes were not significant, results support that the exposed group of Ae. albopictus were developing resistance. It is possible that continued permethrin exposure through additional mosquito generations could lead to a permethrin-resistant colony and further studies are warranted to evaluate this. While beyond the scope of the current study, future studies could also conduct arm-in-cage tests using human volunteers to compare the extent to which mosquito repellency differs between fabrics and repellants such as DEET and others [30,31]. Furthermore, additional types of insecticide-treated fabrics and combinations of repellents and insecticides could be evaluated (e.g. tents, bednets) to improve PTC that could further protect health [30,32,33].