Imported drywall poses potential health, safety risks

							       environment corner




China’s Toxic
 Harvest
Imported drywall poses potential
health, safety risks
By Camille Atrache




T
The issue of toxic Chinese drywall may well             While there is no conclusive evidence to
become the biggest environmental crisis to hit      explain why Chinese drywall gives off sulfur
North America.                                      fumes, its composition may provide a clue.
   Defective Chinese drywall emits hydrogen         Chinese drywall is made with fly ash, a waste
sulphide and other toxic gases that migrate into    product generated in the combustion of coal.
the indoor air, especially when exposed to          The process of “scrubbing” the smokestack
humidity. These sulphide gases are alleged to       emissions creates calcium sulfate or gypsum,
cause serious health conditions and illnesses,      which can then be used to produce drywall. In
such as breathing problems, dizziness,              the U.S., drywall is also made from fly ash but
headaches, bloody nose, fatigue, insomnia and       the material is taken from the smokestack where
eye irritations. According to the U.S. Centers      it is scrubbed, resulting in a cleaner product. In
for Disease Control and Prevention, prolonged       China, however, the fly ash may be obtained
exposure to the compounds in the drywall,           before it makes its way to the smokestack. This
particularly high levels of carbon disulfide, can   creates a “less refined” product.
cause chest pains, affect the nervous system and
even result in death.                               remedying the effects
   As the sulphur in the drywall off-gases it       The controversy surrounding Chinese drywall
produces a noxious odour, which does not            relates to products brought into the U.S.
dissipate. It also creates a corrosive atmosphere   between 2001 and 2007. It is estimated that
that requires immediate attention. Chinese          hundreds of millions of sheets of the defective
drywall has been reported to corrode metals and     drywall were imported by the U.S., with as
cause significant damage to HVAC systems,           much as 929,000 square metres of Chinese
metal plumbing components, electrical wiring,       drywall arriving in Canada through Vancouver,
light bulbs and fixtures, smoke detectors and       all bound for Canadian destinations mainly in
other appliances.                                   Lower Mainland, B.C., though there is
   It has been estimated that as few as three       evidence that some made its way to the Prairie
sheets of drywall in a 1,500-square-foot space      provinces and Toronto.
can be enough to contaminate it to the point of        Properties built or renovated with                so they will also have to be destroyed and
making it uninhabitable.                            contaminated Chinese drywall cannot be               replaced. Unlike airborne hazardous materials,
   So far, most complaints about Chinese            repaired. The only possible fix for affected areas   such as lead-based paint and asbestos,
drywall have come from the southern U.S.            is to have tenants move out for several weeks,       phosphogypsum-based drywall cannot be
states, where a warm, humid climate encourages      gut the entire space and then rebuild the            “sealed” with a coat of paint.
the emission of sulfur fumes. In dryer, cooler      interior. In addition, because surrounding areas
climates, it may be years before people begin to    may have become contaminated by the sulphide         Camille Atrache is chief operating officer and
see the health and safety risks associated with     gases, these areas will also have to be removed      partner at Tri-Phase Environment Inc. For more
this material.                                      and replaced. Anything within the space may          information, contact Camille at 905.823.7965 or
                                                    have been contaminated by the sulphide gases,        catrache@pcbdisposal.com.
the Suspected culprit
When compared to its American counterpart,               Indications of Toxic Chinese Drywall
Chinese drywall has shown to contain
higher levels of sulfuric and organic                      Foul, sulfurous “rotten egg” odour coming from walls.
compounds as well as traces of strontium
sulfide. Strontium sulfide is a grey powder                Continuous, inexplicable failures of air conditioning coils, HVAC units or
that reacts with acids to emit hydrogen                    appliances beyond anything normal.
sulfide gas or a “rotten egg” odour when                   Black corrosion in electrical wiring in the walls
exposed to moist air. Chinese drywall has
also been found to contain higher levels of                Metal in contact with relatively new drywall is corroding quickly.
hydrogen sulfide, carbonyl sulfide and
carbon disulf ide than American-made                       Severe upper respiratory problems, nose bleeds, headaches or other potentially
dry wall. All of these compounds are                       serious medical conditions.
potentially toxic and carbon disulfide in                  Drywall is newer than 2001.
liquid form is extremely flammable.
18 Building Strategies