Which Mosquito Repellents are safe for use.

A Community Health

How to Control Mosquito

Part 5: Mosquito (insect) Repellent

How to seek safe and effective ways of preventing mosquito bites

The best way to reduce mosquito-borne diseases is through mosquito control and personal protection. We can do a few things to reduce the number of mosquito bites that we get while enjoying the outdoors. Firstly, wear clothing that covers most of your body, secondly, use a mosquito repellent, beside mosquito repellents and clothing, we can try to control the mosquito population, mosquitoes need water to breed and will use any source of standing water.

An insect repellent or a mosquito repellent is a substance applied to skin, clothing, or other surfaces which discourages insects (and arthropods in general) from landing or climbing on that surface. It has been estimated that 300 to 400 compounds are released from the body as by-products of metabolism and that more than 100 volatile compounds can be detected in human breath. Carbon dioxide and lactic acid are the two best-studied mosquito attractants, carbon dioxide, released mainly from breath but also from skin, serves as a long-range airborne attractant and can be detected by mosquitoes at distances of up to 36 meters. Lactic acid, in combination with carbon dioxide, is also an attractant. Mosquitoes have chemo-receptors on their antennae that are stimulated by lactic acid. Usually insect repellents work by masking human scent, or by using a scent which insects naturally avoid. Permethrin is different in that it is actually a contact insecticide.

Insect repellents help prevent and control the outbreak of insect-borne diseases such as malaria, Lyme disease, Dengue fever, bubonic plague, and West Nile fever. Pest animals commonly serving as vectors for disease include the insects flea, fly, and mosquito; and the arachnid tick.

Female mosquitoes bite people and animals because they need the protein found in blood to help develop their eggs. Mosquitoes are attracted to people by skin odors and carbon dioxide from breath. The active ingredients in repellents make the person unattractive for feeding. Repellents do not kill mosquitoes. Repellents are effective only at short distances from the treated surface, so we may still see mosquitoes flying nearby.

To be effective, a repellent must show an optimal degree of volatility, making it possible for an effective repellent vapor concentration to be maintained at the skin surface without evaporating so quickly that it loses its effectiveness. Many factors play a role in how effective any repellent is, including the frequency and uniformity of application, the number and species of the organisms attempting to bite, the user's inherent attractiveness to blood-sucking arthropods, and the overall activity level of the potential host. Abrasion from clothing, evaporation and absorption from the skin surface, wash-off from sweat or rain, higher temperatures, or a windy environment all decrease repellent effectiveness. Each 10°C increase in temperature can lead to as much as a 50% reduction in protection time. The repellents currently available must be applied to all exposed areas of skin; unprotected skin a few centimeters away from a treated area can be attacked by hungry mosquitoes

Synthetic repellents tend to be more effective and longer lasting than 'natural' repellents, However, some plant-based repellents are comparable to, or somewhat better than synthetics - depending on the formula, Essential oil repellents can be short-lived in their effectiveness, since essential oils can evaporate completely.

A test of various insect repellents by an independent consumer organization found that repellents containing DEET or picaridin are more effective than repellents with 'natural' active ingredients. All the synthetics gave almost 100% repellency for the first 2 hours, where the natural repellent products were most effective for the first 30-60 minutes, and required reapplication to be effective over several hours. However, some products in the market like essential oil candle and natural herb mosquito coil can give protection to an entire room up to 8 hours.

For protection against mosquitos, the U.S. Centers for Disease Control issued a statement in May 2008 recommending equally DEET at a concentration of 7.5 percent to 100 percent, Picaridin, oil of lemon eucalyptus and IR3535 for skin. Lower DEET concentrations are sufficient for most outdoor protection, and a 15-percent concentration is recommended for children. Permethrin is recommended for clothing, gear, or bed nets. When DEET-based repellents are applied in combination with permethrin-treated clothing, protection against bites of nearly 100% can be achieved.

Common insect repellents :

[1] Chemical compounds:

1. DEET (N,N-diethyl-m-toluamide), inhibit the mosquito’s chemo-receptor.

DEET / N,N-diethyl-m-toluamide

N,N-diethyl-m-toluamide, or N,N-diethyl-3-methylbenzamide (DEET) is the most effective, remains the gold standard of currently available insect repellents. This substance was discovered and developed by scientists at the U.S. Department of Agriculture and was patented by the U.S. Army in 1946. It was subsequently registered for use by the general public in 1957. It is a broad-spectrum repellent that is effective against mosquitoes, biting flies, chiggers, fleas, and ticks. Twenty years of empirical testing of more than 20 000 other compounds has not resulted in another marketed chemical product with the duration of protection and broad-spectrum effectiveness of DEET. This substance has a remarkable safety profile after 40 years used by millions of people worldwide, but toxic reactions can occur, someone cannot use DEET as a mosquito repellent due to skin irritation or to its potential to damage things like plastic, more than 30 studies were conducted to assess acute, chronic, and subchronic toxicity; mutagenicity; oncogenicity; and developmental, reproductive, and neurologic toxicity The results of these studies did not require any change to the product to comply with EPA safety standards, nor did they indicate any new toxicities with normal use. Studies of high doses of DEET orally administered to mice and rats did not reveal any potential in humans for teratogenicity or oncogenicity.

DEET is an effective active ingredient found in many repellent products and in a variety of formulations, including solutions, lotions, creams, gels, aerosol and pump sprays, and impregnated towelettes, in 5% to 100% concentrations.

• A product containing 23.8% DEET provided an average of 5 hours of protection from mosquito bites.
• A product containing 20% DEET provided almost 4 hours of protection
• A product with 6.65% DEET provided almost 2 hours of protection
• Products with 4.75% DEET were both able to provide roughly 1 and a half hour of protection.

Autan of SC Johnson contains 12,50% DEET

Soffell contains 13,00% DEET

2. Permethrin : an effective pesticide, is for use on clothing only, never apply it to our skin, it is a neurotoxin !
3. Picaridin, also known as Icaridin/ Bayrepel / KBR 3023, derives from pepper. Picaridin is derived from pepper and has been approved for use in the US since 2005. It is available in some versions of Avon® Skin So Soft lotions, and sold as Cutter Advanced Insect Repellent too. Though this mosquito repellent is not quite as effective as DEET, it can be used on infants two months or older, and it has a smell that many people find pleasant or at least less off-putting than DEET. Some claim picaridin is just as effective as DEET, but these claims are difficult to prove because both chemicals can be used at different concentration levels.
4. Vitamin B-1 (Thiamin) : Some studies suggest that taking thiamine (vitamin B1) 25 mg to 50 mg three times per day is effective in reducing mosquito bites. This safe vitamin apparently produces a skin odor that is not detectable by humans, but is disagreeable to pregnant mosquitoes, It seems to be especially effective for those people with large allergic reactions. Thiamine takes about 2 weeks before the odor fully saturates the skin. Vitamin B1. Consistant anecdotal evidence suggests that mozzies hate the smell of this vitamin.

[2] Essential Oils:

1. Essential oil of the lemon eucalyptus and its active ingredient p-menthane-3,8-diol (PMD), Plant-based repellents are generally less effective than DEET-based products, but CDC found oil of lemon eucalyptus to be more effective than other plant-based treatments, product containing 40% oil of lemon eucalyptus was just as effective as products containing high concentrations of DEET.
2. Citronella oil : effectiveness in repelling Aedes aegypti, but requires reapplication after 30-60 minutes.
3. Catnip Oil / Nepetalactone, the essential oil in catnip that gives the plant its characteristic odor, is about ten times more effective at repelling mosquitoes than DEET
4. Neem oil : is mosquito repellent for up to 12 hours.

Electronic Repellent :

Electronic repellents utilize one to two sound frequencies (ultrasound / inaudibly high frequency sounds) to simulate dragonflies and other male mosquitoes, creating a competitive environment for the blood-sucking female, these devices come in a compact unit that we can take anywhere for protection. Some units even have a built-in red flashlight for nighttime use.

Electric Mosquito Repellent :

A most effective way to keep a room free of mosquitoes and other small pests all night long by heat, releases natural Pyrethrins smokeless into the air, killing mosquitoes in the room, repelling those outside. Using a chip in an electrical mosquito vaporizer, contains upto 0,5% volatile natural pyrethrins to kill and repel mosquitoes.

Mosquito Coils :

To kill & repel Mosquito

Burning mosquito coils indoors generates smoke that can control mosquitoes effectively, the smoke due to emission of fine particles (particulate) may contain pollutants of health concern that exceed health-based air quality standards, they contain many volatile organic compounds (VOC), like formaldehyde, including carcinogens and suspected carcinogens, in the smoke of mosquito coils, the particles pollutants are fine and ultrafine.

Ingredient of Mosquito Coils :

1. Pyrethroid / Synthetic Pyrethrins : Contain : 0,1% - 0.3% Alletrin, D-Alletrin, D-trans Allethrin, bio-Allethrin and esbio-Allethrin,

and fragrances of perfumes: popular flower fragrances such as Lavender, Sandalwood.

2. Pyrethrum flower : Environment-friendly (Eco-friendly) Mosquito Coils :Contain : 0,2% - 0,5% Natural dried pulverized Pyrethrum flowers.
3. Combination of natural Pyrethris and synthetic PyrethroidsContain : 0,2% natural Pyrethrins + 0,1% synthetic pyrethroid D-Allethrin.

How safe are mosquito coils?

The growing menace of mosquitoes has forced people to turn to mosquito repellents in the form of body lotions, creams, coils and mats. For many families burning Mosquito Coils are a daily ritual. Mosquito Coils which use synthetic pyrethroids like Allethrin are effective in controlling the mosquitoes’ bites, the fumes emitted by the Coils are toxic for mosquitoes but safe for human beings.

The proper use of Mosquito Coils, burning at temperature of about 80° C, the smoke from the Coils prevent the mosquitoes from entering the room, while those mosquitoes already inside the room are expelled or knocked down and killed, the chemicals used in these Mosquito repellents are nerve poison. they affect the nervous systems of mosquitoes.

Prolonged use of Mosquito Coils are harmful for several organs in the human body, they can lead to corneal damage, shortness of breath, asthma and even damage the liver in the long run, affect male as well as female fertility. Allethrin affects human beings adversely, but very slowly , and the effect depends upon the weight of the person. There is no danger for heavy persons but light weight children may be affected.

Don’t use Moquito Coils eveyday, use only in a limited of time,

best use 2 hours before sleeping !

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Do Insecticides & Pesticides no harm to human beings?

How to choose more user friendly Insecticides?

Natural Sources Mosquito Repellents.

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