Wearable Sampler To Check Exposure To Nanoparticles

Reports have emerged that factory workers may damage their health when they inhale nanoparticles and microparticles. But little data exist on how much individuals are exposed to, particularly for nanoparticles. Now researchers in Taiwan and the U.S. have developed what they say is the first personal sampler to collect nano- and microparticles (Environ. Sci. Technol., DOI: 10.1021/es204580f).

Chuen-Jinn Tsai at the National Chiao Tung University and his colleagues linked sampling technologies in series. First, a tiny cyclonic vacuum, like those in bagless vacuum cleaners, catches particles over 4 µm wide, which are too heavy to follow the spinning air in the cylindrical cyclone. The cyclone pushes these microparticles to the side walls, where they fall and are collected. Next, particles bigger than 100 nm in diameter collect in the second part of the sampler, called a micro-orifice impactor. In it, air blows through 137 thin nozzles and pushes particles onto a collection plate. Finally the smallest nanoparticles, those that are too light to be pushed onto the impactor’s plate, blow through and get caught in a filter.

In a lab, the researchers can analyze particles caught in each part of the sampler by gravimetric weighing and chemical analysis. In a test of the device’s accuracy, the scientists found their sampler worked as well in characterizing particles of aluminum oxide and liquid oleic acid as the cyclone and impactor each did separately.

The sampler stands just over 10 cm tall. It is small enough to be worn by a worker, who would simply turn on a tiny pump to start it. Tsai hopes to make the sampler commercially available and is in licensing talks with two companies.