First days in Wilpattu House:2012

 The first time I ever was direct North of Puttalam was in 2010.  My dear classmate Shantha Weerakoon suggested we drive thru the gravel road thru Wilpattu had just opened.   Anyway he could not come because his dogs were having problems.

So I chatted with my mother till about 12pm.  Next day was Sinhala Tamil New Year. so stocked up on booze on the way.  Had a Nissan Wingroad (rental) and very low.  The 30Km Puttalam to EVK took me 1.5 hrs.  The road was not gravel, not tarred either.  By the time I got to  EVK  the road had closed at 3pm.   So slept in the car.  Next day had a early morning bath in Nelum Wewa  and then crossed Wilpattu.  Took 2+ hours to cross the 40km across the Park.

This is the Dry Zone of Sri Lanka, no rain from around April to late October.  However, thanks to the ancient Sinhalese Kings, this part of Sri Lanka has been Environmentally Engineered since around 300BC.  eg Abhayawewa built by King Pandukabhaya.  Walk at most a kilometer and there is a reservoir.

Always had a yen for the Dry Zone of Sri Lanka.  So after seeing Nelum Wewa thought I would buy some land around. When I sounded the idea to others, most said it was stupid.  Mostly because it was civil war borderlands. One of my perfect gentleman bosses Nihal de Silva, author and photographer got blown  by a LTTE landmine inside the National Parjk.

Around July 2011 had decided to buy land in EVK.   My good old pal Shantha Weerakoon was intrigued always wants to see new out of the way places.  Other classmates were going on a Safari next day. There was no entrance to the park from EVK till bout 2015.

Anyway Weera and I came to EVK,  Weera  to check out the area.  Me to check out three properties  the local contact had arranged.  Local contact played me out big time, but thats part of the learning curve as an outsider even in your on country.

So, even tho many said I was paying too much I paid much extra for going rate.  Waterfront etc.

Anyway by Sept 2011 had bought the property. 

So around end Sept came with another classmate, Dushyntha Peter  and we brought  my tent along.
There was no electricity, or running water.  We walked down to the river did some of our three S's (shit.shower and shave).  I preferred doing my swim pre dawn or post dusk, so oxford style.

Mohammed and Murugan. The road thru Wilpattu closes at 3:00 pm. This is the water tower for Eluvankulam, I slept here on the camp bed (booru anda) seen just behind Murugan.

කරවලකැබිල්ල. Bignay (Philippines) wild cherry and currant tree (Antidesma bunius)

Planted a few days ago. Sinhala කරවලකැබිල්ල  Karawalakebilla  (Tamil: நாளைதளி Nolaidali ) Bignay (Philippines), Mao Luang,  wild cherry and currant tree (Antidesma bunius). Attracts birds and can become a 15m (45 foot) tree.

The skin of the fruit has red juice, while the white pulp has colorless juice. The fruit contains a light-colored seed. The fruit has a sour taste similar to that of the cranberry when immature, and a tart but sweet taste when ripe. This tree is cultivated across its native range and the fruits are most often used for making wine and tea and is also used to make jams and jellies. 

Rich in antioxidants and anticancer properties. The leaves can be eaten and can be included in a salad mix.

Antidesma bunius
https://en.wikipedia.org/wiki/Antidesma_bunius

Video in Sinhala
https://www.youtube.com/watch?v=lqkgn3iDNwM&t=182s

Covid: Droplets vs Aerosols and UV sterilization

Recent studies have shown that COVID-19 is not transmitted  just by droplets but also by aerosols. (eg Twang et al, 2021  and Samet et 2021.  Aerosols can disperse as far as 10m (33 feet).  Thats about the size of a small waiting room or small office. (WHO dragged its foot about accepting aerosol transmission of COVID-19 and cost many deaths.)

If transmission is only by droplets, then masks, hand washing and sanitizer can reduce transmission.  However, if it is aerosol airborne then other precautions are needed.  Sterile clean rooms are probably crucial to contain the highly infectious Indian variant B.1.617.2. 

For aerosol sterilization, proper ventilation and air that is not re circulated would reduce transmission. For space that is not properly ventilated, such as air conditioned rooms an option is sterilization by UV radiation.  Sterilization by UV is now not very expensive, and commonly available home and house supply stores.

Waiting Room/Small Office 
Air Purifiers with UV  that can purify a 1,000 sq ft in one hour (or 600 sq ft in 30 minutes) is about USD 100.  Not giving a link to a particular item or store, as would appear endorsement.  A search for "air purifiers with UV" will give many results.

Isolation Beds
Isolation rooms maybe to expensive in numbers.  A cheap alternative might isolation beds with in-going and outgoing air being UV sterilized.   Basically a plastic canopy covering for the bed and adaptive plumbing to two UV air purifiers  One for air into bed enclosure.  The other for air to be sucked out of bed enclosure.

Important Note
Combining UVC irradiation to recirculating air filtration might enhance elimination of airborne microorganisms.
UVC irradiation (100–280 nm) is highly mutagenic for microorganisms and its efficacy is dependent oh the dose (J/m²) which is composed of

• a) UVC intensity (W/m²) and
• b) exposure time (s),
• c) the wavelength (254 nm),
• d) relative humidity (RH) and
• e) the susceptibility of microorganisms to UVC irradiation

Through the formation of thymidine dimers, UVC functions as a mutagen and leads to damage of the microbial DNA. Several studies demonstrated the virucidal and bactericidal effectiveness of UVC irradiation  (see pig facility citation for more detail)

Some References of UV Sterilization of Air

Wai et al (2020) BMC Infectious Diseases volume 20; 127

In the disinfection tests against seasonal influenza viruses H1N1 and H3N2, we also demonstrated that viral load could be effectively reduced by 4-log10 folds after 20 min VUV illumination and this also satisfied the criterion of valid germicidal result. Additionally, more than 3-log10 reduction in viral load can be attained with < 10 min of treatment.

Eisenhofel et al (2019) PLOS ONE, November 2019  (This was on pig facility)

Tests at laboratory scale were performed using aerosols of Staphylococcus (S.) aureus, Actinobacillus pleuropneumoniae, porcine parvovirus (PPV) and porcine reproductive and respiratory syndrome virus. We varied relative humidity (RH) to evaluate its effect on UVC irradiation efficiency. In addition, viability of pathogens inside the filter material was determined over up to six months. UVC-combined air filtration resulted in a more than 99% reduction of viral and bacterial particles. RH had no influence on UVC efficiency. Viability in the filter matter varied depending on the pathogen used and RH with S. aureus and PPV being most resistant.

Tim Sandle (2020) American Pharmaceutical Review June 2020 (does not seem peer reviewed)

Effectivity of HEPA Filters to Remove Viruses from Air Entering Cleanrooms

sereno barr-kumarakulasinghe, May 24th, 2021

Also published on
https://www.linkedin.com/pulse/covid-droplets-vs-aerosols-uv-sterilization-sereno-barr-kumar/

pdf version available
https://drive.google.com/file/d/1iORwmRm0jK75J7IU6Ft0hDbvKcgPkOiG/view?usp=sharing


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The 60-Year-Old Scientific Screwup That Helped Covid Kill

All pandemic long, scientists brawled over how the virus spreads. Droplets! No, aerosols!heart of the fight was a teensy error with huge consequences.

They ticked through a growing list of superspreading events in restaurants, call centers, cruise ships, and a choir rehearsal, instances where people got sick even when they were across the room from a contagious person. The incidents contradicted the WHO’s main safety guidelines of keeping 3 to 6 feet of distance between people and frequent handwashing. If SARS-CoV-2 traveled only in large droplets that immediately fell to the ground, as the WHO was saying,

Marr was no stranger to being ignored by members of the medical establishment. Often seen as an epistemic trespasser, she was used to persevering through skepticism and outright rejection. 

https://www.wired.com/story/the-teeny-tiny-scientific-screwup-that-helped-covid-kill/