When the Fog Clears: Mosquito Control, Dengue Fever & The Environme...

Not every species is thriving with climate change, but the mosquitoes certainly are.

From January to June 2020, Thailand (where we currently live) has already had more than 6,000 confirmed Dengue Fever cases - almost double the number of Covid19 Cases. 11 children have died.

Dengue is a viral infection carried by the Aedes aegypti mosquito, which also transmits Zika, yellow fever and chikungunya. Although dengue is responsible for some 20,000 deaths globally each year, it hasn’t received the attention of deadlier diseases like malaria. That is changing, though, as an uptick in outbreaks in the last decade has exposed the need for new research. Roughly half the world’s population lives in areas susceptible to dengue. A recent study published in Nature Microbiology predicts that by 2080, as many as 2.25 billion more people — or 60 percent of the global population — will be at risk. Source

In Thailand, Dengue Fever requires mandatory reporting by the Office of Public Health. Immediately after a confirmed Dengue diagnosis, "fogging" is required by law within 200 meters of the address of the sick person. Which means random teams of council workers suddenly turn up unannounced and FOG.

What does that mean?

They carry backpacks mixed with a pesticide and diesel, and use a leaf-blower type of apparatus to spray pesticide EVERYWHERE. In drains, foliage, around houses....

This was the view from my upstairs window, just 2 days ago:

Please note the completely unprotected worker, with his ineffective cloth mask around his chin and his bare hands.

In the past, fogging has been done using DDT (thank you America for your valuable contribution to Asia!) and then Malathion. But we're moved on somewhat (thankfully!) and these days the mos commonly used pesticide of choice is Cypermethrin - derived from a flower.

Is it effective? Oh yes.

In outdoor simulated pools cypermethrin 40% EC was consistently effective against larvae and pupae of Ae. stimulans at 10 g AI/ha and Culex spp. at 50 g AI/ha. When stickleback fish were tested, no mortality occurred at the lowest effective dosage in each trial. The residual toxicity of cypermethrin increased with dosage and was much higher in a test at 8 degrees C than at 20 degrees C. In natural snowmelt pools, cypermethrin at 20 g AI/ha provided 92-100% control of Aedes spp. larvae and pupae by 7 days after treatment. Non-target amphipod, anostracan, cladoceran and insect populations were usually reduced 80-100% while copepods, ostracods and hydracarinid mites were generally less affected. No significant mortality of caged stickleback fish occurred in these pools. Source

The scary part of that statement is the 80-100% reduction in other insect populations. Cypermethrin is deadly to bees and to our environment. It stays in our soils, killing the vital microbes, and it poisons our waterways. The mosquito larvae it doesn't kill bounce back within 7 days, but the natural mosquito natural predators don't. Which means each time we-they fog, we-they are compounding the mosquito problem for next week, next year.

What are the legally required Safety Data Sheet warnings on every container of Cypermethrin?

H301: Toxic if swallowed.
H315: Causes skin irritation.
H317: May cause an allergic skin reaction.
H332: Harmful if inhaled.
H335: May cause respiratory irritation.
H373: May cause damage to {organs} through prolonged or repeated exposure.
H400: Very toxic to aquatic life.
H410: Very toxic to aquatic life with long lasting effects.

But surely diluting it with diesel, which helps it stay on wet surfaces, will make it less hazardous?

Exposure to diesel exhaust in small amounts can cause: Irritation to the eyes and nose, headache & nausea. Breathing diesel fuel vapors or exhaust for a long time can cause:

Respiratory disease.

Kidney damage.

Increased blood pressure.

Lowering of the blood's ability to clot.

Cancer. Source

Let me be clear, this is not only a Thai problem. This is a global issue. Many, many countries use these pesticides for mosquito control.

Let me remind you again of the projection (from above) for Dengue Fever over the next 60 years:

"by 2080, as many as 2.25 billion more people — or 60 percent of the global population — will be at risk".

Globally, we need urgent discussions about chemicals in our food chains, in our communities, in the air we breathe. We need to discuss how to RE-BALANCE insect and bird populations, not kill more of them. Because we are killing our important pollinators - those important creatures which enable our food to grow.

What Can You Do?

Educate Yourself.
Buy only ORGANIC food;
Insist on accountability when governments use toxins which threaten our natural world;
Get involved in your local environmental action group;
Teach & educate your children, your community;
Go and live far away from urban government control.

If you can't avoid fogging in your neighbourhood, please cover your nose and mouth immediately and leave the area if you can. Protect your pets. Detox your body actively, and often. Drink lots of clean water. Refuse to buy or eat foods from fresh markets which are fogged, as the veggies and fruit are not covered.

The standard argument thrown back to non-Thai people questioning harmful practices is to leave if we don't like it. I am a mother and my young Thai daughter is harmed by these dangerous chemicals, as is the natural world I hope she will enjoy with her children. It's my responsibility to speak up, inform and educate, not just in Thailand but in the GLOBAL WORLD of which I am a citizen.

Together we need better, natural, global solutions as our climates change and mosquitoes thrive.