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I did a very in depth amount of personal research about insect repellent in preparation for a long-term trip into an area of the world where Zika, Dengue, and Malaria are all endemic. To summarize my findings I would say the following:

1. Spray your clothes, not your skin.

2. If you don't want to overdo it, make sure in particular to spray your neck/collar, your cuffs/wrists, your ankles/socks/shoes. As you might imagine, most bugs get to your skin where it's exposed and get under your clothes at the openings, and the areas closer to the ground are more exposed.

3. Use Picaridin (sometimes called Icaridin). It needs to be a minimum 20% concentration by volume to be effective.

4. If you are willing, pre-treat your clothing with Permethrin 6+hrs prior to wear

5. If you are going to apply insect repellent directly to your skin, don't use a spray, use a lotion, sprays are for clothing.

6. Wear a hat that's been treated with Permethrin

That's pretty much it. If you do these things you'll be fine. Obviously you don't want to put repellent on your entire skin every day, but having your outer clothes treated with Permethrin and then putting a small amount of repellent lotion on your skin where your outer clothes have openings and wearing non-treated underwear/undershirt can do a lot and is relatively safe. DEET is very effective, but toxic to humans, and some insects are becoming resistant, Picaridin is similarly effective but with a shorter fall-off time (needs to be re-applied more often) and significantly lower toxicity and without natural resistance in the insect population.

Thank you; this is more-credible-sounding advice.

Would you apply that same advice to walking in the city, in the middle of the day, in a state where some nasty mosquito-borne disease has been detected this year. Or would you modify the advice for that?

I put on insect repellent every time I go outside during the summer, but I have split my time living between Texas and Colorado, both of which have wells of endemic mosquito-borne illnesses (unfortunately). Besides mosquitos though, I am much more worried about ticks, biting flies, and grass fleas/chiggers which are also commonplace once you walk into a natural area, even in the city. I would say it really depends on the city you live in though, some cities mass-spray public areas, and some do not. Here in Colorado they avoid using insect suppressants and repellents in mass sprays due to negative impacts on the population of pollinators, so any natural area or park in the city is definitely a danger zone if you don't take any precautions yourself. Relevant context is I live next to a natural area and can walk out my front door and into 2600 acres of natural area that's right in the middle of the city, it's where I go walking my dog (before she recently passed) and where I ride my bike on the trails.

Great info; thank you.

> Also suspicious is that protocol is missing. For example, how do you use bug spray

Realistically, the people who do not read the instructions literally on the side of the bottle they are applying to themselves are certainly not going to go back and pull up a news article they saw a day, week or month ago and try to get the instructions from there. Never mind how error prone that would be as each "repellent" chemical has different instructions and warnings (permethrin goes on clothes, while DEET goes on your skin for instance).

>Every time I see the advice to wear insect-repellent every time going outdoors, I wonder whether that's actually good advice, and what the health pros&cons are.

The insect repellent isn't just for mosquitos. DEET is fairly effective against ticks and black flies as well, neither of which is particularly fun to deal with. Whether you need to apply it or not depends a lot on the environment and climate but I always keep a bottle of DEET based repellent and Afterbite in the car just in case.

>Also suspicious is that protocol is missing. For example, how do you use bug spray, where on body, do you really need it every time you go outside, when do you wash it off and how, what about clothing, why do only sometimes they say not to use such-and-such spray on children and pregnant/nursing women (but other times they don't), does advice differ for urban vs. rural, what are the side effects or adverse interactions to know, etc.

There's more then one kind of repellent, and their delivery is going to change the formula as well; lotion isn't going to be be same formulation is an aerosol or manual spray, even if the repellent itself is the same. Is it any real surprise that there isn't going to be some universal direction for application with so much variety?

It seems awfully paranoid to leap from “the protocol isn’t totally clear” to “do they think I believe everything on the internet?!”.

Read the bottle. Put it on. If you’re in an area prone to Lyme disease it’ll be far worse than any tiny degree of poison from bug spray.

For example: You just instructed people to put on bug repellent, without qualifying that.

Then you appended a supporting rationale that applies only to some people, in support of your advice.

So it's unclear whether you're speaking from a public health strategy, informed by expert knowledge on pertinent topics, and trying to minimize net harm over a large population, when you can use only a few broadcast words.

Or whether you have almost no idea what you're talking about, but are simply parroting your own interpretation of those few words you heard.

I'm speaking as the kind of person who was fine getting Covid vaccine, as soon as I heard doctors in general were giving it to their own families.

I'm asking why I keep seeing this particular blanket advice about bug repellent, and what does it actually mean.

For example, if we take some of the uses of this soundbite advice literally, it would imply that the situation is so dire that even incurring a population percentage of known adverse effects from people who will follow these instructions without reading the back of the bottle and second-guessing, is worthwhile.

I think I need a straight answer about what it means, from someone who knows what they're talking about, including about any public health and communications calculus involved.

This brinksmanship of determining if bug spray is a good idea or not is a pretty moronic approach to understanding… anything.

You can do your own research if you want, but your personal opinion is of no importance to anyone and it’s not surprising that someone hasn’t hand delivered you a special report on an issue that most people consider mundane and not important.

If you’re wandering through woods that have equine encephalitis mosquitos and Lyme disease ticks then wear some bug spray. You don’t need the full toxicity report to build your priors that these really serious diseases are much more threatening than these extremely common products. MA has both of these and pretty much everyone here not living in a purely urban environment knows someone that has gotten seriously ill from Lyme. Nobody knows anyone that is seriously ill from bug spray.

If you’re going to be doing this every day, maybe consider putting some effort in, but otherwise just read the bottle. Your priors have to be so wildly distorted from reality for your line of argument here to be sensible.

> I'm speaking as the kind of person who was fine getting Covid vaccine, as soon as I heard doctors in general were giving it to their own families.

Sorry, but that’s a really stupid heuristic that implies your primary concern is that the doctors are lying to you. Paranoia, as I mentioned above.

I think that you uncharitably misinterpreted some honest and reasonable comments, that your own view isn't as informed and reasoned as you think, and that you unloaded an unnecessary personal attack to discourage genuine curiosity and concern.