Chinese cities are growing fast which often results in a sacrifice in the quality of building materials used. This can lead to potentially toxic, unhealthy indoor environments,
especially in newer buildings. Walls, flooring, furniture, paints, sealants and coatings all emit toxic chemicals, a situation dramatically worsened when high air pollution
increases the amount of toxins inhaled attached to dust particles.
Which harmful substances can be found in buildings?
VOCs (Volatile Organic Compounds) - VOCs are typically released from building materials and include formaldehyde, acetaldehyde, isocyanates, benzene, toluene and xylene. They
are emitted mostly from coatings, sealants, finishes, paints, glues and pressed wood furniture
SVOCs (Semi-Volatile Organic Compounds) - SVOCs are emitted more slowly and over longer periods of time than VOCs. They readily attach to dust particles and are thus
inhaled. Typical compounds are phthalates present as softeners, halogenated flame retardants (for example PCB), perfluorochemicals found in water- and dust-repellant coatings and
polyaliphatic hydrocarbons (PAHs) found in tar-based glues and sealants
Biological contaminants - poorly-constructed buildings may contain "temperature bridges" in walls and ceilings which result in moisture traps where mold and bacteria are
prone to develop. Biological contaminants are the most common triggers for asthma and allergies
Heavy metals - these can be found in roofing, solder material, dyes for paints and textiles; stabilizers used in vinyl plastics, wire insulation and other PVC products.
Lead, mercury, antimony, chromium and cadmium are the most commonly-occurring heavy metals found in this context.
Asbestos - this is a natural mineral fiber and a respiratory irritant known to cause chronic obstructive pulmonary disease (COPD) or "asbestosis" and more
seriously, a type of lung cancer.. It can be found in insulation, pipes, cement and cardboard materials. Additionally, dangerous amounts of asbestos can be released after building activities
such as renovation and demolition.
Artificial mineral fibers - these are found in similar settings and have similar effects to asbestos
Which construction alternatives are safe?
- Adhesives, sealants, paints etc. should be water-based or at least low VOC
- Formaldehyde-free wheatboard and solid wood are safer than composite wood and fiberboard
- For sub-flooring and underlay strawboard, isoboard or mixed materials made from wheat, straw, sugarcane or recycled paper bonded with nontoxic agents, are most suitable
- When possible, choose mechanical fastening over glues
- Marble, granite, concrete, stone and ceramic tile are a safe choice for counter tops
- Ceramic tile, terrazzo, brick, hardwood, pine, natural rubber, true linoleum, colored concrete, cork and bamboo are suitable healthier alternatives to vinyl flooring
- Gypsum-based drywall (Sheetrock) may predispose to mold and emission of toxic gases so a better choice is paper-free gypsum (there are special mold resistant types), plaster or veneer plaster
- Natural insulation materials like cork, wool, cement or plant-based foams are safer than fiberglass, rockwool or polyurethane (PU) based foams
- Beside the choice of materials, the construction method itself (avoiding humidity traps, providing effective insulation, lighting and noise management, effective waste water and
ventilation systems) and the interiors themselves are just as important for a healthy indoor environment