I think you are right but you are not meant to detect them in the open enivironment where workers are exposed.
I understand that benzene was no longer brought into these sites so that any benzene detected must have been produced in-plant by chemical reaction, but again should not be detectable.
The cancer-inducing nature of materials is also a function of the amount of material present.
I remember in another life when i had to read a learned paper about a food coloring called "Herring brown B." The paper supposedly showed "Herring brown B" to be a carcinogen.
However, the amounts of "Herring brown B" fed/injected into rats were enormous, at some significant fraction of their body weight over some period of time (I am sorry but the details are forgotten).
I can't even remember how Herring brown A and Herring brown C compared.
But I remember thinking at the time that at that amount of exposure almost anything could show as a carcinogen.
The chemicals used in fabs are dangerous, especially arsenic. Hydroflouric acid is also very dangerous. The key is to use them without exposing the workers. I guess this study was measuring the concentrations in the air, so the workers are exposed. I wonder how the US fabs measure up.
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Are the design challenges the same as with embedded systems, but with a little developer- and IT-skills added in? What do engineers need to know? Rick Merritt talks with two experts about the tools and best options for designing IoT devices in 2016. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.