Air purifier? - Part 2

WussRedXLi

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What do you use to repel mosquito when you go out? Go out also never apply repellent?

We don't live in a mosquito hotspot. Anyway, apply only when you go to hotspot areas ba. Even then, the risk is not very high nowadays.

We are afraid of dengue though. It's a very bad disease. Can't imagine kids or pregnant women going through that.
Those very old elderly, like > 80 years old, with or without underlying conditions esp those immunocompromised, lagi worst of the lot.
My grandfather admitted to SGH, typical cut coz fell down. Already patched up and recovering, then kena cough, then pneumonia, medications did not help. Then uplorry. :s22:
If 90++ and kena dengue, that might be the last infection that the person might be seeing even though dengue could be relatively mild, but note the word relatively mild ie to the general population. :s22:

PS. Just been thinking abt the prev article...

1 x mosquito coil (allethrin). No significant mortality vs control
1 x metofluthrin tower, close to 100% mortality.
Conditions : Opened windows (so metofluthrin is damn able to kill mozzies in a semi-enclosed space, but not on repellency/expellency).

40X more potent. Lets say you are using 2 vaporisers, that becomes 20X.

Can we hit 20X higher concentration than metofluthrin in a closed windows setting within 4-8 hrs so that it can accumulate vs opened windows setting? I'd guesstimate it to be relatively easy to hit 20X.

This is esp so for those new BTO bedrooms / units which are ultra small.
 

super365

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Is the OFF Clip-on repeller (metoflurin) more powerful than Baygon liquid repeller (prallethrin)?
 

WussRedXLi

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Is the OFF Clip-on repeller (metoflurin) more powerful than Baygon liquid repeller (prallethrin)?

With respect to the specific mosquito Aedes Aegypti that was reared in the lab that they have gotten from Penang (ie really same stuff as we have in SG) in which the study i posted above has researched on, yes.

Prallerthrin is 2X more potent than Allethrin.
Metofluthrin is up to 40X more potent than Allethrin.

Is sure die in a fully enclosed room.

With 2X Allethrin vaporisers and 8-hrs, we could still be just a wee bit off from 100% mortality...but i'll take it nevertheless.

Issue - it's fast but expensive. Even if you gun 1 x fan for 1 hr, it can do 12 days/nights only. 6.95 for 12 refills.

But then again cost is relative. If it's the parents with young infants/immuno-compromised elderly, or in families in which there is a pregnant woman, then seriously $$$ could be somewhat secondary i guess.
 

WussRedXLi

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It's just a foil covering the treated evaporation area.
Not sure if it's re-stickable or not.

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Gixxerfied

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The off! clip on i was reading a review, it's good only if one stays in the same spot..If happen to move then have to wait 1-2 sec for the shield to form up again..

In short, it's good only if u're stationary..

Anyway, when i was in my wife's hometown in malaysia over last weekend..I spray some off! repellent(Their side only 15% deet while sg is 18%)..I was sitting outside then i notice a aedes mozzie landing on my arm, nv poke then flew to another spot on my arm then flew to another before flying off..
 

WussRedXLi

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The off! clip on i was reading a review, it's good only if one stays in the same spot..If happen to move then have to wait 1-2 sec for the shield to form up again..

In short, it's good only if u're stationary..


Anyway, when i was in my wife's hometown in malaysia over last weekend..I spray some off! repellent(Their side only 15% deet while sg is 18%)..I was sitting outside then i notice a aedes mozzie landing on my arm, nv poke then flew to another spot on my arm then flew to another before flying off..

Yep...i posted quite a few youtube vids also, real world on the ground tests. But that is not unexpected, in fact this "issue" plagues all aerial type repellents. From your few tens of KG of chrysanthemum flowers placed at the intake of Air Purifiers to mosquito coils to 20 cans of Anti-Moz herbal based stuff. :)

I give you a real world scenario that's easy to understand. You go to a temple into the enclosed hall with 1000 sticks of incense so it's real smokey and full of smell. Stand upwind, will you smell any incense smoke? Barely. Go to the other end, i think most would be buay tahan.
So in those scenarios at home with wind, do not expect any repellency effect.

In fact, nope....in terms of REPELLENCY (not mortality) the video review that i gave to super365 showed that even the Thermalcell allethrin mat beat it in terms of repellency. In fact, the Off clip-on did not work at all in terms of repellency, close to ZERO effect in a dead calm setting. Thermacell mat has an allethrin concentration of 48mg/mat, a bit more than the typical 36mg/mat stuff generally that's sold out there.

And the article that i posted showed that it did not show any repellency or expellency effect in an enclosed room with windows opened. But it did attract the mozzies, in which case they were killed during the test. :s13:

Read here : http://www.ajtmh.org/content/81/1/94.full

(mozzies used in the tests were Aedes aegypti sourced from Penang so it's 100% relevant)

But apparently it's really super effective to KILL mosquitoes in an extended duration and not the typical repellency situation that's measured in seconds. Just that it's expensive. If you are willing to dump 6hrs worth of fan operation into an enclosed room (with mosquito window screens so no issue of external mozzies flying in when you ventilate afterwards), it's 100% mortality without doubt. That'd be at a cost of S$1.70, assuming AAA rechargeable batteries. If you use AAA alkalines, then it'd be like $1 more. Nope, not the typical AA batteries, so don't think that you are safe with Amazonbasics AA NiMHs. :s13:
Per 6hr runtime.

And once opened, must finish using within 14 days. Probably at the 13th day mark after taking away the foil, it'd suffer from quite a significant % of natural evaporation as well (which is $$$). Coz the chemical is somewhat volatile at room temp, many times more than say allethrin. Eg, alcohol is a very volatile at room temps.

And nope, it's not like the bottled repellents from Shieldtox/Mortein/Baygon, cannot put the cap back on. Also, those suffer from many times less natural evaporation anyway, that's why can last 60 days with 8hrs of heated operation per day.


I read that it's a pretty new chemical, so i guess some coy patented it....and decided to charge a lot for it since it's so darn effective at the target organisms. Let me go google.
 
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WussRedXLi

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http://www.sumitomo-chem.co.jp/english/rd/report/theses/docs/20050200_imi.pdf

Metofluthrin (SumiOne®, Eminence®) is an exciting novel pyrethroid discovered by Sumitomo Chemical Co., Ltd. It was registered in Japan in January 2005 and has now been under worldwide development for environmental health use.

Metofluthrin has extremely high knockdown activity against various insect pests especially mosquitoes, as well as relatively high volatility and low mammalian toxicity. This is applicable to not only existing formulations and devices such as a mosquito coil and a liquid vaporizer, but also various new type products such as a fan vaporizer, a paper emanator and a resin emanator.

It is noted that knockdown activity of Metofluthrin is more than 40 times higher than that of d-allethrin against southern house mosquitoes in a mosquito coil formulation. This paper describes the discovery story, insecticidal efficacies in various formulations, synthetic methods and safety evaluations of Metofluthrin.


Note this is knockdown efficacy and lethal efficacy, not repellency or expellency (those latter 2 are tested and reported in the study, shared in the above post )

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Table 10 has especially important info for both metofluthrin and d-allethrin.
Note, it is for Culex mosquitoes. Both this Table and the scietific study in the link 1 post above stated that Culex had longer knockdown time etc than Aedes, hypothesized that it's due to the much larger size of the Culex.

Note in Table 9, it seems that prallethrin is much better than d-allethrin, but this is coz it's a topical application, ie applied onto the mosquito. Previously i have also shared that prallethrin has approx the same lethal time timing vs d-allethrin, just that the concentration of d-allethrin was twice higher than prallethrin.

Also note the 28 cubic metre chamber space, which is approximately our BTO MBR room size. This one is different from the previous study, in which the mosquito coil (d-allethrin) did not statistically differ from the control room in terms of mortality. Also note, mortality is not equal to knockdown...but i guess knockdown is the precusor to mortality.
 
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WussRedXLi

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From the below, it seems that the smaller mosquito Aedes xxxx species is even more susceptible to metofluthrin vs other phyrethrins. Really pulls away from the rest with Aedes, as compared to the Culex.
(ie extremely effective against Aedes mosquitoes)

But note, if you get such stuff to want to kill other pests, eg ants/mites, then the lead with metofluthrin might not be as much, or it might be even better.

You can see transfluthrin in some of the aerosol spray insecticide cans.
PS. Do not use aerosol spray insecticides if you have young kids, pregnant mothers, nursing women at home, unless if you can 99% clean up the spray residues "hotspots" afterwards. Vapor release is totally different, even if there is condensation on any surface in the room, it is magnitudes better managed + extremely spread out that there probably is no risk at all.

Metofluthrin is also magnitudes safer even if there are minute amounts of residue condensation in the room surface if used in an enclosed space, coz it's volatile at room temp as compared to other ***thrins. Just a short duration airing would suffice.

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WussRedXLi

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Gixxerfield, the more i read and the more i understand, the more i think that this is the holy grail. It kills the aedes completely, like a blue light electric zapper + lure does but without the drawbacks of it (that is if it manages to lure and kill it in the day time, which probably needs a couple of days to have any meaningful/repeatable results).

If one is in a hotspot area and finds that there is a mozzie trapped in the house despite having a mosquito screen, this is it. You don't have to worry if it's a confirmed kill or if it's going to work or not like the electric zapper with lure....

Close all windows and smoke it out, lethality is confirmed. Easy, simple, safe (assuming no pax in the room and airing it for a very short while after treatment) and 100% result.

You can also do so with a couple of allethrin/prallerthrin vaporizers as well. But need longer duration, ie more planning. And airing duration is relatively longer compared to metofluthrin.

Issue is, it's not cheap per shot. But the allethrin/prallethrin route is not many times cheaper also, though they are still cheaper if compared so in the long run and if you can afford to wait that 8-10hrs, the A or P chemicals make more sense esp since it can be stored at room temperature much longer after opening. (methofluthrin need to just use it all up within 14 days after opening)
Methofluthrin might cost ~ $10 for a whole HDB house per shot. But for those who can afford it, this is it!
 
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tildveryn

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The off! clip on i was reading a review, it's good only if one stays in the same spot..If happen to move then have to wait 1-2 sec for the shield to form up again..

In short, it's good only if u're stationary..

Anyway, when i was in my wife's hometown in malaysia over last weekend..I spray some off! repellent(Their side only 15% deet while sg is 18%)..I was sitting outside then i notice a aedes mozzie landing on my arm, nv poke then flew to another spot on my arm then flew to another before flying off..

hahahhaha..... lol how u know its aedes mozzie
 

WussRedXLi

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Another one.....repellency not good. Same findings like the scientific report i posted before and also the youtube real world test.

But if used for killing (mortality) in a fully enclosed room (no pax in the room please), it should be way better and way faster than the rest. And also any minute residues in the room would evaporate away very very fast, maciam like water evaporation on a surface here like that.

http://www.consumerreports.org/cro/...t/health/clip-on-repellent/overview/index.htm

Testers are bugged by clip-on repellent
Last reviewed: August 2010

The claim
The label on Off Clip-on Mosquito Repellent, $10, claims "head to toe protection up to 12 hours." The device, which uses a fan to circulate repellent, attaches to a waistband, belt, or purse. It's approved as a spatial repellent (not for skin). Its active ingredient is metofluthrin, a neurotoxin. The label says, "Avoid breathing vapor," but it's hard to imagine how, with the repellent swirling around you.

The check
We attached Off Clip-on repellent to the waists of four testers for 12 minutes every hour and sent them one at a time into screened enclosures with 1,000 hungry, disease-free mosquitoes. (We added 500 new mosquitoes for each tester's subsequent session.) Between sessions, we kept the devices running but stored them away from the testers and enclosures.

Bottom line
Ouch. Although Off Clip-on initially reduced the number of mosquitoes near our testers, two of them still received one bite each during their first session. That's far less protection than the 7-plus hours of complete protection we've seen with many skin-applied repellents. By the third session (2 hours after the device was activated), we had stopped testing on all four subjects because of bites. Instead of clipping on this Off device, consider buying one of the highly rated sprays from our recent tests: Off Deep Woods Sportsmen II, Cutter Backwoods Unscented, Off Family Care Smooth & Dry, 3M Ultrathon (all with deet); Repel Plant Based Lemon Eucalyptus; or Natrapel 8-Hour with picaridin.
 

WussRedXLi

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New idea for those willing to try. Get the Off Clip-on REFILL for $6.95, 2 pack.
So each pack is $3.50 cost.

Tear off the tab, leave it. Put a decent USB fan + powerbank and blow on it for 12hrs. I think the evaporation is even higher than the clip-on device so it would be used up well within 12hrs.

1pc confirm kill for mozzies. You can try 2pcs even, kill until cannot kill further.

Note, must close and lock all windows/doors. eg the yard louvre windows, best if you can stick some newspaper + masking tape to cover. Door gaps also cover. Really no horse run then.

For those with an extreme need for lethality, eg pregnant women in hotspots etc.

Note : remember to ensure no pax in the house during operation. And no fishes.
 

WussRedXLi

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Latest info for those on d-trans allethrin...i found this.

http://www.chowyang.com/uploads/2/4/3/5/24359966/011.pdf

Summary. 70cm (0.343 cu metres) chamber, 0.5mg of d-trans allethrin released into the chamber, mortality of aedes aegypti.

Extrapolated to our Sheildtox 2.0% d-trans allethrin, it's 14.38mg of d-trans allethrin released with 8hrs operation time. Typical MBR of 3.4 x 4.2 x 2.8m room = 40 cu metre. Assuming 60% air vol (less 40% furnitures = 24 cu metre of air space.

0.5mg d-trans allethrin = 0.343 cu metre
1 vaporizer 14.38mg = 9.86 cu metre treatment.
2 vaporizers = 19.72 cy metre treatment.
3 vaporizers = 29.58 cu metre treatment.

3 vaporizers should give you 50% mortality for 14-15 days age aedes aegypti (penang) and 72% mortality for 19-20 days. Younger mosquitos are lower.

But the good news include longevity being reduced by 40% after this exposure. The percentage of blood engorgement activity for Ae. aegypti was reduced to less than 55% after exposure.

So the results are encouraging for d-trans allethrin vaporizers, but not perfect.

BTW, can see that the performance of d-trans allethrin (Shieldtox and Mortien repellents) is double that of d-allethrin. This is important as earlier there's info of prallethrin vs d-allethrin (90% vs 60% mortality), d-allethrin at double the concentration so can say that it's equivalent to the same concentration of d-trans allethrin ie 1.6%.

Note the performance of 0.2% d-allethrin vs 0.1% d-trans allethrin, mortality numbers are literally neck-to-neck.

I suspect the 2.6% d-trans allethrin Mortien outperforms the 1.6% prallethrin Baygon. And also double the vol so double the useful days.


So to achieve as close to 100%, you might want to vapour 12 hours (4hrs longer than 8hrs) with 3 vaporizers. Even if it survives the vapours, the longevity and biting tendency are close to half reduced.
4-5 vapourizers would be ideal.

Can't help in the local market context....

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WussRedXLi

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Repellency is weak for the off clip-on (but don't mistake for mortality in enclosed area)

 

greythorne

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Hi anyone here knows how to connect xiaomi air purifier 2? I managed to connect but it shows as offline in the app
 

WussRedXLi

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http://www.channelnewsasia.com/news...s-killed-more-than-100-000-study/3138276.html

Southeast Asian haze crisis killed more than 100,000: Study
Posted 19 Sep 2016 14:07 Updated 19 Sep 2016 14:10

JAKARTA: A smog outbreak in Southeast Asia last year may have caused more than 100,000 premature deaths, according to a new study released Monday (Sep 19) that triggered calls for action to tackle the "killer haze".

Researchers from Harvard and Columbia universities in the US estimated there were more than 90,000 early deaths in Indonesia in areas closest to haze-belching fires, and several thousand more in neighbouring Singapore and Malaysia.

The new estimate, reached using a complex analytical model, is far higher than the previous official death toll given by authorities of just 19 deaths in Indonesia.

"If nothing changes, this killer haze will carry on taking a terrible toll, year after year," said Greenpeace Indonesia forest campaigner Yuyun Indradi.

"Failure to act immediately to stem the loss of life would be a crime."

A spokesman for Indonesia's environment ministry did not immediately have any comment.

Indonesian authorities have previously insisted they are stepping up haze-fighting efforts, through such actions as banning the granting of new land for palm oil plantations and establishing an agency to restore devastated peatlands.

The haze is an annual problem caused by fires set in forest and on carbon-rich peatland in Indonesia to quickly and cheaply clear land for palm oil and pulpwood plantations.

The blazes occur mainly on Indonesia's western Sumatra island and the Indonesian part of Borneo, with monsoon winds typically blowing the haze over Singapore and Malaysia.

But last year's fires were among the worst in memory and cloaked large parts of the region in choking smog for weeks, causing huge numbers to fall ill and sending diplomatic tensions soaring.

The new study to be published in journal Environmental Research Letters, which combined satellite data with models of health impacts from smoke exposure and readings from pollution monitoring stations, estimated that 100,300 had died prematurely due to last year's fires across the three countries.

They estimated there were 91,600 deaths in Indonesia, 6,500 in Malaysia and 2,200 in Singapore.


INFANTS AT RISK

Greenpeace hailed a "groundbreaking" study they said for the first time gave a detailed breakdown of deaths from last year's fires, but cautioned that the figure was a "conservative estimate".

It only looked at health impacts on adults and the effect of dangerous fine-particulate matter, known as PM 2.5. It did not examine the effect on youngsters or of the other toxins produced by the blazes.

In reality, infants are some of the most at risk from the haze, said Nursyam Ibrahim, from the West Kalimantan province branch of the Indonesian Medical Association on Borneo.

"We are the doctors who care for the vulnerable groups exposed to toxic smoke in every medical centre, and we know how awful it is to see the disease symptoms experienced by babies and children in our care," said Ibrahim.

The study found an increase in the number of fires in peatland and in timber concessions in 2015, compared to the last major haze outbreak in 2006, but also found that the number of fires in palm oil plantations fell.

Shannon Koplitz, a Harvard scientist who worked on the study, said she also hoped the model they had developed could help those involved with tackling the annual blazes make quick decisions "as extreme haze events are unfolding".

Last year's haze outbreak was the worst since 1997 due to a strong El Nino weather system, which created tinder-dry conditions in Indonesia and made peatland and forests more vulnerable to going up in flames.

- AFP
 
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WussRedXLi

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Toxic haze in Southeast Asia killed 100,000, study says

fd3380f2-4c2d-4c50-a74f-68b3f2a1ab20.img


Toxic haze that spread across Southeast Asia from Indonesian forest fires last year caused the deaths of about 100,000 people across the region, according to the first academic study of the health impact of the smog.

The death toll was concentrated in Indonesia, which had about 92,000 excess deaths from persistent haze that choked the region between July and October, according to researchers at Harvard and Columbia.

The study published on Monday in Environmental Research Letters, a leading academic journal, linked haze from the fires to about 6,500 deaths in Malaysia and 2200 in Singapore.

The deaths were mainly caused by cardiovascular disease, though there were also some deaths from respiratory disease, the researchers say.

The researchers focused on adult mortality, and are now working on a further study to examine the impact on children.

There was likely to have been an increase in child deaths from pneumonia in Indonesia due to the 2015 haze, according to Sam Myers, senior research scientist at Harvard School of Public Health and one of the study’s authors.

The findings are likely to fuel political tensions over the annual blight on the region, which is driven by Indonesian smallholders or plantation owners clearing land for farming and palm oil or paper production.

Yuyun Indradi, a Greenpeace campaigner in Indonesia, said: "If nothing changes, this killer haze will carry on taking a terrible toll.

"Industry and government must take real action to stop forest clearing and peatland drainage for plantations."

Singapore has urged Indonesia to assist in collective action to tackle companies that clear land by burning, but this has met with a prickly response from Jakarta, which has accused its neighbour of meddling in domestic affairs.

Indonesia's president Joko Widodo said in April that palm oil growers should boost productivity rather than clearing further forest land.

Jakarta has already imposed a moratorium on clearing primary forest and converting peatland for other uses, but campaigners say enforcement of this restriction has been weak.

The researchers quantified emissions from the fires, then used weather data to track the spread of the haze. The scientists used data for mortality rates to determine how many of the deaths last year were due to exposure to fine particles known to be hazardous to health.

Dr Myers said: “Essentially, we asked how much mortality would have occurred that year without the fires and how much would occur with the fires and reported the difference.”

While this is the first academic study of the 2015 Southeast Asian haze, previous research has shown the deadly consequences to human health of air pollution.

Globally, deaths from infectious diseases have declined in recent years as more people have access to clean water, improved sanitation, vaccines, mosquito nets and medicines.

However air pollution and other environmental factors remain a significant cause of death in poor countries in Southeast Asia and the western Pacific, according to the World Health Organisation.

Palm oil, a key ingredient in popular consumer products ranging from toothpaste to lipstick, has been linked to “slash and burn” forest clearance in Indonesia.

Producers of palm oil have come under intense pressure from corporate buyers, investors and environmental groups to ensure their supply chains are sustainable.

Last week, some of the world’s biggest agricultural businesses — including major palm oil producers — came together in an alliance that aims to raise environmental standards in the sector.

https://www.ft.com/content/925a02d4-7e17-11e6-8e50-8ec15fb462f4
 
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