We Need a Safe Breathing #Water Act – #Legionella #aerosols #IAQ

Forty years ago this month, more than 200 cases of Legionnaires disease, resulting in 29 deaths, occurred at hotel hosting an American Legion conference in Philadelphia — giving the disease its name and the American public its first media-amplified look at an outbreak. 

Four decades later we’re still being exposed to Legionella bacteria — the rate of reported occurrences has quadrupled since 2000 according to a recent CDC report — but we’ve done little to stifle its primary vector: water in the air.

After months of investigation through the summer and into the fall of 1976, officials traced the Philadelphia outbreak to contaminated water in the hotel’s cooling towers, which exposed the people to the bacteria via the air conditioning system.

Some things never change.

According to the CDC report, issued in May, most cases in the last 15 years were attributed to exposure to Legionella-contaminated potable water, frequently in aerosol form. This sort of exposure can occur from air conditioners, showers, decorative fountains, humidifiers and other places where running or falling water creates a spray that can be inhaled.

Legionella is not the only infectious agent that can multiply in water systems and cause outbreaks when water is aerosolized and inhaled. Outbreaks of non-tuberculosis Mycobacterium have also been traced to water in aerosol form. 

It’s time for a Safe Breathing Water Act.

While the Safe Drinking Water Act of 1974 and its subsequent amendments has significantly reduced the public’s exposure to ingested, infectious agents, such as viruses and harmful bacteria and chemicals, the crisis in Flint, Michigan has shown us that gaps in public health protection remain.

What was not well understood at the time of the Safe Drinking Water Act is that the pipes through which water is conveyed may serve as incubators for some bacteria, a number of which can cause illness if aerosols containing these bacteria are inhaled. 

Today bacterial amplification and exposure processes are better understood. We have also identified practices that can minimize chances of bacterial occurrence, such as  maintaining appropriate disinfection concentrations, keeping levels of nutrients (including those that can be released via corrosion) low and reducing leaks.

It is time to consider amending the Safe Drinking Water Act to include a “safe breathing water” provisions, which would incorporate our best knowledge and practice to reduce the public’s risk of inhaling Legionella, Mycobacteria and other respiratory pathogens that can be amplified in water systems and transmitted in aerosol form. 

As decades of public health engineering practice have shown, prevention is more effective when implemented closer to the source of the problem. So A Safe Breathing Water Act would include closer control of distribution systems and building piping, as well as restrictions on how systems with the potential to generate large volumes of aerosol are managed. 

It would also require licensing those who are responsible for maintaining water quality in large buildings. And buildings, with licensed operators, could be allowed to engage in local treatment without being considered public water systems. The act would set water quality contaminant limits that can be monitored and enforced at end-user taps and intakes of aerosol-generating equipment so as to protect not just people who drink water but also those who unwittingly breathe it as an aerosol.

This would be a suitable recognition of the lessons we’ve learned in the course of 40 years since the mysterious outbreak in Philadelphia made us reconsider all the ways we are exposed to water. 

#Denver Union Station and #LoDo – a model?

I had a wonderful two day visit this past week to Denver, where I stayed a block and a half from Union Station.  I have not been in Denver since the light rail to the airport opened this spring.  The change in the “feel” of the LoDo (Lower Downtown) area is fantastic.  I was particularly impressed with the Union Station redevelopment itself. There are several important features that development of other urban train stations could take note of (are you listening Philadelphia 30th Street Station and  NYC Penn Station).  As an untrained observer of the urban environment, the following in particular stand out to me:

  1. There is a diversion of heavy automobile through traffic away from the area, in favor of pedestrian and bike access
  2. Seemless integration of rail, light rail and busses.  Also integration with a free 16th Street shuttle (think if Philadelphia had a free Market St shuttle from 30th Street to City Hall or even the Delaware river)
  3. Both in the station and surrounds, there are many local eateries, coffee shops, etc (not a single national franchise in the station!).  There is a hotel in the station as well as several within a 2 block radius.  This project has clearly been catalytic for development in the 5-10 block radius (the LoDo neighborhood).

It was wonderful to be able to walk from the airport baggage claim to the Denver RTD station at the airport to take a comfortable train ride – 37 minutes or so, with 15 minute headways, to Union Station, then walk 2 blocks to my hotel – without having to navigate a single step or even a curb.  This is intelligent multimodal planning. It is still not without glitches; one of my colleagues at the meeting had a two hour delay on his train due to a power failure.  So advice is to plan ahead heading to the airport.  But I had a smooth ride both ways.

Other cities should think about this as a model, although Denver has fewer short and long-haul Amtrak trains than Philadelphia or New York.







Outside of Union Station at night.  From: union-greathall-tooltip.jpg
















Interior of old trainhall (old ticket windows are now a bar).  From: https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=imgres&cd=&cad=rja&uact=8&ved=0ahUKEwjV26vW4-bNAhVCPz4KHZJCDAMQjRwIBw&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FDenver_Union_Station&psig=AFQjCNGIfjYDWg5oQA2tqZWwZyJRNp2O5w&ust=1468167337248878