When I was an undergraduate student in architecture, one of my classmates built a model out of lead. He obsessed over the material, which was heavy yet soft and pliable, and easily manipulated yet carried a visual gravitas. We students and our professors gave our approval for this material experimentation.
A few years earlier, in 1986, the Minneapolis-based Walker Art Center hosted a retrospective exhibition of the work of Frank Gehry, FAIA, that includes at least two occupiable structures clad in lead. The New York Times architecture critic Paul Goldberger raved about the final installation in particular, a wood frame construction resembling the section of a massive fish, covered in lead scales. “The big, constructed fish at the Walker exhibition … on its inside is a space of startling power, its converging, rounded shape providing an intense sense of focus that totally alters our normal perceptions of architectural space,” Goldberger wrote. "And the exterior is at once an ordinary, everyday sight and a very strange one… It forces us to view a conventional object as a kind of pure form, divorced from its usual set of meanings.”
I came to know Gehry’s lead fish in 2008, when I began teaching at the University of Minnesota. The central atrium in Rapson Hall had become the ultimate home of the installation, this “ordinary and extraordinary” object, functioning as a sculpture and a shelter. Students regularly used the fish as an informal meeting room, and it also served as a potent visual anchor within a square space. Yet the structure’s lead cladding proved to be its downfall: Students were forbidden from touching the shingles, and cleaning the fish required university staff to wear hazmat gear. Ultimately, the sculpture was dismantled and put into storage.
Lead’s toxicity is well-established. According to the World Health Organization, lead is “a cumulative toxicant that affects multiple body systems and is particularly harmful to young children.” Once lead enters the body, it is taken up by various organs such as the liver, brain, and bones. Lead poisoning can have devastating consequences, and no level of exposure is considered safe. Per a recent analysis, a mere 10 micrograms per deciliter of lead in young children results in lowering their IQ by an entire grade level—with irreversible effects.
In response to influential mid-20th-century studies, Western nations began prohibiting the sale of lead paint in the 1950s, and regulated lead additives in gasoline two decades later. Yet problems persist. A recent article in The Economist reports continuing health risks posed by the corrosion of lead pipes, as seen in Flint, Mich., as well as the unabated manufacture and sale of lead paint in emerging nations. The widespread existence of lead paint in the U.S., primarily in older houses in less affluent neighborhoods, also represents a perennial hazard. According to a 2011 country-wide housing survey, one in seven U.S. houses has exposed lead paint.
Presumably, my college classmate and Gehry were both aware of lead’s potential risks yet remained infatuated with the material’s expressive potential. Meanwhile, paint suppliers in Kenya evidently prefer to continue selling lead-rich paint than to find alternative products. In both cases, human health is considered peripheral to function, economics, and aesthetics.
The curious choice to subordinate health prevails in the ongoing use of other materials. The International Living Future Institute (ILFI) recognizes the worst offenders in its Red List, a “greatest hits” of toxic substances common to the building industry. The inventory, which includes lead, also consists of: alkylphenols, asbestos, formaldehyde, halogenated fire retardants, mercury, polyvinyl chloride and its permutations, volatile organic compounds in wet applied products, and wood treatments containing creosote, arsenic, or pentachlorophenol. This alphabet soup of noxious substances and their variants includes both highly regulated materials, such as asbestos, and mainstream products, such as formaldehyde.
With the Red List, the ILFI and other environmental advocacy organizations aim to reduce the demand for toxic substances—particularly those that remain commercially available—by encouraging their avoidance. Yet significant challenges to phase out these materials remain.
A concern that remains conspicuously absent from AEC industry discussions about the Red List materials is their ultimate fate. Eschewing toxic substances is one matter, but what should happen to the existing inventory? For all the talk of embracing a cradle-to-cradle or circular economy, such materials should decidedly not be treated as technical nutrients for new products, but rather as technical poisons that must be removed from material cycles.
Or should they? According to the International Lead Association, lead is one of the most frequently recycled materials due to its prevalent use in batteries. Many manufacturers may argue that this kind of material recapture, conducted in a safe and highly controlled manner, is permissible. However, end-of-life realities always include some percentage of products entering the waste stream. In the U.S., some states treat lead as a hazardous waste while others allow consumers to discard lead products in regular household trash. Once lead leaches into groundwater, its negative effects not only persist but expand.
A more favorable approach considers the utilization of natural ecosystems to detoxify our contaminated material flows. Phytoremediation involves the use of living plants to remove, diminish, or contain polluted soil and groundwater. A study prepared for the U.S. Environmental Protection Agency describes phytoremediation strategies for lead (and mercury); these strategies include phytoextraction, or the removal and sequestration of toxins, via plants like Indian Mustard.
Landscape architects are well aware of such strategies and, as indicated in Niall Kirkwood and Kate Kennen’s book Phyto: Principles and Resources for Site Remediation and Landscape Design (Routledge, 2015), are increasingly putting them into practice. Phytoremediation processes are slow, complex, and imperfect—for example, phytoextraction poisons the plants in the process. Yet this is one of the very few methods that address the end stage of Red List substances responsibly. Architects would do well to learn more about such practices and help undo the harm caused by their deliberate choices.