How extreme weather events affect your health

Last week, Hurricane Maria battered parts of the Caribbean before heading up the east coast of North America.  Like Irma and Harvey before it, record-breaking rainfall caused severe flooding.  But the receding floodwaters in places like Florida and Texas are giving way to some serious health problems and risks.   

Check out our extensive coverage on White Coat, Black Art.

The power is still out all over Puerto Rico, so the stories we're getting are sketchy.  The mayor of San Juan told the Washington Post that people are like prisoners in their own homes.  There was a report on Twitter of 200 seniors virtually trapped in a 14-storey building with no power save for a few hours on a generator. The building had a broken water pump, no access to clean drinking water, and poor sanitation.  Volunteers found one man lying on the floor of a hallway, unable to get up. Four needed to be evacuated because of dehydration.  Some needed dialysis.  The local hospital – steps away – could not accept any more patients. 9-1-1 was down because the phones didn't work.  Officials say it will take three weeks for hospitals to regain power.

In Florida and Texas, the immediate risk is that people with diabetes and other chronic diseases have missed regular medical appointments.  The stress of living through the flood tends to make diseases like these get worse.  At Ben Taub Hospital in Houston – which was in the path of Harvey – an official told me that they have patients who missed regular treatments for cancer and other serious diseases.  The floodwaters themselves lead to other risks.  The main one is infections caused by close contact with raw sewage and water from the Gulf Coast. In Florida, people have reportedly gotten infected cuts and scrapes after wading through floodwaters; some had to be admitted to hospital.

There is a bacterium called Vibrio vulnificus that lives in the Gulf Coast.  The bacterium tends to infect people who are chronically ill and those with weak immune systems.  It's one of the causes of necrotizing fasciitis or 'flesh-eating disease.'  Doctors say there was an increase in cases of Vibrio following Hurricane Katrina, and they expect to see cases following Irma and Harvey.  They're warning residents to stay away from receding floodwaters if possible.

Then, there are illnesses that at carried by mosquitoes.  In the past few months, we've been hearing about cases of the Zika virus in parts of Florida and Texas. The Zika virus is transmitted by a bite from an Aedes aegypti mosquito infected with the virus.  Zika is already present in both Florida and Texas.  There have been eleven cases of the virus confirmed in Houston this year.  None were caused by local transmission of the virus.  Florida has had 33 cases in which people had symptoms of Zika – mainly a flu-like illness with fever, rash, plus joint aches and pains.  It's likely that many more people have been infected but did not have symptoms. Unfortunately, the two areas in the U.S. where Aedes aegypti are most likely to breed and multiply just happen to be south Florida and Texas.  The silver lining is that storms tend to affect the breeding cycle of mosquitoes, and so there may not be enough time for them to multiply before it gets cold.  Officials promise to do a lot of spraying of insecticide.  

Some experts think it's more likely that Florida and Texas will see an increase in West Nile and Eastern equine encephalitis – both of which are entrenched in the North American bird and mosquito population.  It's more likely that cases of Zika, Dengue and chikungunya will spike in parts of the Caribbean.

There are other potential health risks, such as mold. Both Irma and Harvey dumped record-breaking rainfall on Florida and Texas respectively.  Mold thrives in the moisture that remains in homes after floodwaters recede.  A World Health Organization report concluded that mold can trigger coughing and shortness of breath.  It can worsen asthma and trigger respiratory infections.  Following Katrina, the U.S. Centers for Disease Control advised people affected by storms to get rid of mold as soon as possible.  But the problem with mold is that it's can show up in homes that are only partly flooded, and can be hard to detect.

Chemical exposure is another potential risk.  In Texas, the other concern that Harvey flooded or damaged oil refineries and chemical plants.  There are fears that Texans may be exposed to benzene and other cancer-causing chemicals.  That's a health risk that likely won't show up for years. 

These are the physical ailments. The psychological impact is almost incalculable.  The sheer panic of wondering if you and your loved ones will make it out alright is enormously stressful.  There's actual loss of life and loss of physical health.  Harvey has cost tens of thousands of people in Texas their homes.  The flooding destroyed a million vehicles.  We know from studies that following Katrina, a bit less than one in five adults and nearly two in five children in New Orleans had nightmares and flashbacks.  Experts anticipate up to half the people directly affected by Irma and Harvey will have short-term anxiety, and as many as five to 15 per cent will end up having post-traumatic stress disorder.

If there is one positive note, it's that the people in charge of disaster planning are learning.   Extreme weather events like Katrina and Sandy have brought at wealth of knowledge on how to prepare for them.  The doctors, nurses and administrators in charge need to take courses and carry out drills and simulations.  With Sandy, there was enough time to increase flood protection.  At Ben Taub Hospital in Houston, they used the time until the storm began to discharge patients well enough to go home.  Figuring out what to do when the power goes out has led to creative solutions like handwriting or printing out in advance a summary of the patient's condition in case they need to be transferred or evacuated.  At NYU, when the elevators failed, they used sleds to get patients down the stairs.  

Preparation pays off.  The initial death tolls from Harvey and Irma are much lower than Katrina and Sandy.  Climate scientists say we should expect more extreme weather events, so there will probably be a lot more opportunities to put these hard-fought lessons into practice.