Keeping Our Distance In The Outdoors

By: Janet Andersen, Chairman of Avalonia’s Groton Town Committee

I’m a retired statistician with a lot of years working in infectious diseases including TB that has similar routes of transmission as COVID-19. I feel strongly about prevention of this nasty virus, especially as many of us are in the ‘high risk’ ages. The hope is that we will see the backside of this toward the end of May. I feel all but the most critical Avalonia land work can be put on hold knowing we’ll have some big briar messes to deal with and boundary walks when it’s leafy and buggy, but we will be healthy (and alive) to do these.

Gory details of why below, but my family and I observe a minimum 12’ as ‘social distance’ from non-family and prefer 20’ or more. I know Town Committee (TC) members and other Groton volunteers are on the trails doing work, and my hearty thanks! I did trail work today myself. The TC March meeting agenda had a good list of one-off and maintenance projects for the spring and summer. I am concerned with folks using pointy things (chain saws, scythes, etc), moving large rocks or doing boundary walks with only 6’ separation at our implied or actual request.

The gory details: The definition that “6’ = social distance” is months old and assumes C-19 is transmitted by droplets that will fall or dry up in that 6’ before it gets to the next person’s face. There now is strong evidence C-19 is transmitted when aerosolized (fine mist). The 6’ rule also doesn’t factor wind. I walk at 4+ mph. In one second, I cover 5.9’. If you are 6’ behind me, you are breathing what I exhaled/coughed a second ago and are betting on the droplets being large enough to fall fast and that aerosols aren’t a problem. If I’m walking into a 4mph wind, you’re breathing my cloud in half a second. Ick.

Some of the same analysis goes into work parties. If people are 6’ apart, a 4 mph wind gives you what someone else upwind breathed out 1 second ago…if they coughed in your direction, less. 8 mph wind and it’s half a second for the cloud to hit you. There have been some studies of groups that carefully observed the 6’ apart rule pretty much on a grid and there was transmission with the people in the middle hit worst. I observe a minimum 12’ rule and prefer 20’ (or 50’!) because of the above. In my opinion, it would be difficult to do a boundary walk 12-20’ apart … you can’t see each other’s phone or map, root around a rock together to find a drill hole, or ‘hold this’ to help post signage, etc. Individual trail work of 2 or maybe 3 people a shout away from each other does make sense. We’ll want to avoid having folks out far from help with nobody to dial 911…but then if you need 911, you are taking ER time away from COVID management. So while we are under “stay safe, stay home”, I suggest to leave the choice to do trail work completely informal and not a directed activity so nobody feels any pressure.