During volatilization, also known as off-gassing, chemicals change into a gas and release into the air. Volatile organic compounds (VOCs), commonly found in wet-applied materials and composite wood products, are chemicals that most readily off-gas.
Degradation is the chemical or physical breakdown of materials. When building materials degrade, they may release substances or form new compounds. For example, the molecules in plastics degrade and release chemicals as they age. Chemical degradation may occur through hydrolysis or photodegradation, the breakdown of molecular bonds due to water or sunlight, respectively.
Abrasion, a type of degradation, is the mechanical scratching, scuffing, or rubbing away of a material that results in the release of small particles and dust. Abrasion may be seen in wear patterns, such as in the steps shown here.
Material contents can dissolve, or leach, directly into liquids. Leaching of water-soluble compounds can cause the contamination of water sources, as we have seen with lead pipes. Oil-soluble compounds more typically absorb into skin or end up on dust.
Oxidation describes processes such as burning and rusting. Certain oxidation reactions can release harmful byproducts into the environment. The burning of halogenated chemicals (commonly used in flame retardants) releases dioxins, which are highly toxic Persistent Organic Pollutants (POPs).
Amongst its other consequences, climate change affects the air we breathe. Outdoors, changes in climate increases levels of pollutants (e.g. ground-level ozone), which have strong health effects. These pollutants can also make their way inside, harming indoor air quality.
Chemical inhalation occurs when we breathe in contaminated air, dust, and other airborne particulates. Some building materials as well as construction activities release toxic fumes and VOCs that are particularly prone to inhalation and may lead to a variety of health concerns.
Ingestion through Food
Chemicals in our food or drinks enter our bodies through dietary ingestion. Contamination may come from the tools we use to cook (like toxic PFAS in nonstick pans), food packaging (i.e. bisphenols in a water bottle), agricultural pesticides, or toxics that accumulate through the food chain.
Ingestion can also occur through unintended, non-dietary pathways. We touch countless surfaces every day. Hand-to-mouth ingestion happens when traces of contaminated soil, dust, or other chemicals get into our mouths from our hands. Children’s contact with the floor while crawling, as well as their tendency to put their hands and other objects in their mouths, makes them particularly vulnerable to hand-to-mouth and object-to-mouth exposures.
Toxic substances can be absorbed through oils in our skin and hair follicles. Exposure can happen when we come in contact with contaminated soil, dust, water, or through consumer products composed of chemicals of concern. Children are particularly vulnerable to dermal exposure, as they have greater contact with floor surfaces, where contaminants (e.g., dust) tend to settle.
Newborns may be exposed to toxic chemicals through their mothers’ breast milk. Breast milk has proteins in it that bind to several types of heavy metals. It has also been shown to carry pesticides, neurotoxicants, and other harmful chemicals from mother to baby.
Before they are born, children may already be burdened by toxics. Chemicals of concern can pass from a mother to a developing fetus through the placenta. These chemicals include toxic flame retardants, lead, PFAS, and BPA.
Asthma is a chronic respiratory disease. Asthmagens (chemicals that cause asthma) can be found in a range of building products, including wet-applied paints, finishes, and adhesives. According to the CDC, rates of asthma in the United States have increased since 1980, with over 25 million cases today.
Cancer is the second leading cause of death in the United States (CDC). Exposure to carcinogens such as formaldehyde, perfluorinated compounds, and heavy metals, found in a variety of building materials, may lead to different types of cancer.
Endocrine disruptors are chemicals that interfere with our body’s hormone system. They are linked to a range of health issues, including reduced fertility in men and women. BPA and phthalates, for example, mimic our bodies’ hormones and potentially cause adverse reproductive, developmental, neurological, and immune effects.
Preterm birth, one of the leading causes of infant mortality worldwide, is being linked to exposure to air pollutants during pregnancy. Indoors, chemicals of concern include VOCs, formaldehyde, and benzene. Outdoors, exposure to particulate matter (PM) and other ambient air pollution (PM2.5, PM10, NO2) is also thought to significantly increase preterm births.
Autism Spectrum Disorder (ASD) is a developmental disability that affects 1 in 59 American children. Although autism’s causes are not completely known, environmental factors likely impact children’s likelihood of developing ASD. Recent research shows correlations between ASD and air pollutants, BPA, and mercury.
Millions of people worldwide are overweight or obese. Some endocrine disruptors (chemicals that interfere with our body’s hormone system) have been shown to be obesogens, chemicals that increase the risk of obesity by disrupting our metabolisms. These chemicals include PFCs (perfluorinated chemicals), flame retardants, and phthalates.
Particularly vulnerable to chemicals of concern are children. The amount of time they spend on the floor puts them in close contact with settling toxics, and their immature metabolisms struggle to process the chemicals. Additionally, toxics have a greater impact on their lifelong health because their bodies are still developing.
Fenceline communities, which are zones neighboring industrial facilities that use hazardous chemicals, are vulnerable to chemical spills and environmental pollutants. The residents of these areas are disproportionately Black and Latino, reflecting larger trends of environmental racism in the U.S.
Lower-income populations are disproportionately exposed to substandard building materials and environmental health hazards. In addition, less access to health care often makes this part of the population more vulnerable to chemicals’ toxic effects.
Pregnant Women and Developing Fetuses
Because many harmful chemicals are able to pass through the placenta, a pregnant woman’s exposure to chemicals of concern can affect her fetus as well. In their development, fetuses’ bodies are especially susceptible to toxics, with lifelong consequences on their health.
Manufacturers and Contractors
Building products’ toxic ingredients are most likely to be airborne during manufacturing and construction. Wet-applied products like paints and finishes, which release high levels of VOCs during their application, are especially concerning. Frequent exposure to airborne toxics during fabrication and installation increases workers’ vulnerability to toxic exposures.
Maintenance and Custodial Staff
Tasked with maintaining spaces, keeping indoor air quality high, and preventing pest infestations, building staff and custodial workers often use highly toxic chemicals to meet expectations. In order to avoid repeat exposures to chemicals of concern, it’s important that cleaning and maintenance protocols maintain sanitary environments without the use of hazardous chemicals.
Emergency Response Workers
Fires, floods, and other environmental emergencies are inherently dangerous. Beyond their immediate threats, they increase the toxicity of certain materials.. PVC, for instance, releases toxic dioxins when burned. First responders, who rush to the scene to protect us, are particularly vulnerable to these toxic situations.
We're All Affected
Although some populations are more vulnerable than others, toxics in building products affect all of us. Chemicals of concern infiltrate our air, water, food, and buildings, impacting our world in inescapable ways.
The first step toward choosing healthier materials is asking manufacturers what’s in their products. Ingredient disclosures help designers make healthier choices. Requesting transparency can also drive industry change.
Spread awareness! Educational institutions and spaces can empower the current and next generation of designers by equipping them with knowledge about material health and tools to navigate the landscape. As an initial step, you can make change by sharing information with your colleagues.
Good design is healthy design. By forefronting health considerations throughout the design process, architects and designers have the power to create beautiful, healthier spaces. At HML, we partner with designers, non-profits, developers, and city agencies to demonstrate a health-focused design approach.
Support grassroots organizations working on the frontlines to implement community driven solutions to toxic pollution in our most vulnerable neighborhoods.
Driving change toward healthier designs requires ongoing dialogues among stakeholders and change in practice. Engage with clients, manufacturers, contractors, designers, and maintenance. Initiate these discussions, empower all stakeholders to make informed decisions.
Advocate for Policy
Help drive government change! Legislators have immense power to change regulations that ensure: health is a right, not a privilege. Government-led efforts have prompted change on issues like lead and PFAS in drinking water. Current initiatives include the Green New Deal.
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