A Probable Cause of Asthma

Dear Readers:

It has not been proven what causes asthma in our children, and researchers have not proven the reasons why there has been a dramatic increase in asthma cases worldwide.  So researchers who can find a correlation with other factors often offer their speculative opinions.

In Barbados, incidents of asthma have increased significantly since the 1970’s.  Health researchers have blamed the sub-Saharan African dust and allergens, environmental researchers have blamed pollution, and climate researchers have blamed the climate.

It is very easy and convenient to find a correlation with factors that only God can change.  It allows reputable researchers to go unchallenged and offers no hope to those who are directly affected – mainly the children and their parents.  Since parents are essentially powerless to change the sub-Saharan dust, allergens and the climate, they must resort to treating the symptoms with drugs.

Treating symptoms is not a permanent solution, but it can be an unnecessary lifetime expense.  Therefore, let us turn our attention to this issue in order to bring relief to the sufferers, and to prevent further incidents.

Before we continue, let me note that preparing this article revealed a glaring weakness of peer reviewed documents.  Generally, the reviewer only know as much, or perhaps a little more, of the narrow discipline of their peer, the author.  However, most causal investigations are not confined to only one discipline.  Therefore, single-discipline reviewed research will always be incomplete and substandard.  This should not reflect negatively on the competence of the researcher or the reviewer, but rather, on the effectiveness or the system in which they operate.  I can confidently state that the conclusions of most (if not all) single discipline reviewed causal studies on multi-disciplinary issues that I have read, are as useful as a shoe on a fish.

When trying to solve these types of problems, the most logical place to start is to understand the following.

  • The trend in the number of cases over many years.
  • The variability in cases during any one year
  • The relevant dramatic environmental changes when the symptoms started
  • The relevant environmental changes that increased as the number of cases increased

What environmental factors changed dramatically in the 1970’s across Barbados?  Well, not the climate, not the allergens, and not the sub-Saharan dust.  In Barbados, in was mainly an increase in the construction of concrete-block masonry houses and the purchase of automobiles.

Before, the floors of houses in Barbados were not in direct contact with the ground.  Ground floors in chattel houses and stone masonry houses were normally suspended above the ground as shown below.

House with suspeded floor

Builders constructing concrete-block masonry houses started placing the concrete slab directly on soil as shown below.

Floor on fill

A child sleeping in a room where the floor is in direct contact with the damp soil is not a safe environment.  In recognition of this, national building standards worldwide, including the Caribbean, specified that a Damp Proof Membrane or Vapour Barrier (eg. plastic sheets) be used to prevent moisture from rising through the floor and walls.

Tragically, builders and potential homeowners in Barbados were not made aware of Barbados’ national building standards.  Very few, if any (certainly none that I was aware of before Walbrent College was founded 5 years ago) had a copy of the Barbados National Building Code.  Therefore, either the Damp Proof Membrane was not installed, or it was not installed properly.  In the photo below, the black plastic Damp Proof Membrane is not lapped properly and it is not taped at the laps, allowing moisture to rise.

DPM

In the photo below, the Damp Proof Membrane or Vapour Barrier does not extend over the blocks.  Therefore, moisture can rise up the walls.

DPM not over walls

Therefore, all children in single storey concrete-block masonry houses, and all children sleeping in bedrooms that were located on the ground floor of a two-storey house, were in an unhealthy environment.  If they slept in an unventilated room with the room’s door(s) and window(s) closed, then the risk of harm increased significantly.

 Supporting A Plausible Solution

At this point, the significant increase in the number of houses with the floor in contact with the ground is plausible.  Now, let us see if the trends of asthma cases support our proposition.

Since there is increased rainfall in the rainy season of May to October, the ground floor and walls of houses would normally be damper than during the drier season.  The statistics show that there is an almost doubling of asthma cases in the wetter months of May to October.

Further, the number of asthma cases are always higher in the lower catchment area that drains into the Constitution river, where the water table and damp soil is closer to the surface, than in any other part of Barbados.

While this does not prove causation, it certainly makes ‘concrete slab on ground’ construction method a strong contender.  The proof can come by interviewing the sufferers to see whether they resided in such masonry houses.  It should be noted that poorly installed vapour barriers is reportedly a common problem worldwide.  Therefore, it can explain the general global increase in asthma cases.

Investigating the Increase in Automobiles

For completeness, we should investigate the increase in cars, and thus car exhaust emissions, as a possible cause.  If cars were the reason for the increase in asthma cases, then we would expect to see significantly lower cases in the windward eastern side of the island.  However, generally, there are a higher number of cases per 1,000 people in the better ventilated windward side of the island than on the western side, excluding the Constitution’ river’s drainage catchment area.

Help for All Parents

So what can parents do?  My suggestions follow, which would improve the quality of the interior house environment, even if another reason is later proved to cause asthma.

All new houses should have a properly installed Damp Proofing Membranes (continuous plastic sheet, lapped and taped) under the ground floor slab and walls, to prevent the damp from rising into the house.

All existing houses should have the external walls plastered and waterproofed.  If you are renting, then ask the tenant to do this.  The photo below shows a typical single-storey plastered masonry house.  Note the rising damp areas at the base of the wall.

Plastered house

What you cannot see is that the builder did not plaster all the way to the footings.  Please be advised that this is typical.  Therefore, the walls below the ground are normally damp, and the damp rises into the house – especially if the Damp Proofing Membrane does not extend over the blocks.  Note that the right side of this damp area is drier, only because the soil has been removed.

Unplastered foundation wall

The photo below shows a bituminous waterproofing agent applied to the plastered wall.

Waterproofed wall

I wish you well.

Best regards,

Grenville

Note: All photos are copyrighted by the author.

Advertisements

You are encouraged to present your opinion.

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s