The day of the "iSniff" nears

with new monitors co-developed by Chillrud, Cowin and their respective teams. Each device features technologies designed to pinpoint not only what children are exposed to, but when, where and for how long.

Chillrud is one of eight grantees currently refining personal airborne pollution sensors as part of the National Institute of Environmental Health Service’s (NIEHS) Genes and Environment Initiative — a project aimed at gaining an improved understanding of how genetic factors and environmental exposures influence human disease. “As we were developing the initiative,” says David Balshaw of the NIEHS, “we came to the conclusion that we needed to develop the capacity to monitor individual exposures.”

The gold standard for such devices had traditionally been monitors housed in burdensome backpacks, weighing as much as three kilograms, or about as much as a newborn baby. “This limited us to enthusiastic teenagers, or concerned adults,” Chillrud notes. “You couldn’t really do young kids.” And even with the most eager, compliance was always an issue: Would study subjects consistently lug them around or would they grow tired and leave them sitting at home or in a locker?

Peeples writes that before long, however, terrorism took over as the sensor’s primary obstacle. “My timing was perfect: the Madrid bombing had happened while we were developing the monitor,” Chillrud says. “No one seemed phased much. But when the London bombings happened, and it became apparent that our pack was the same size, the police said, ‘No way. You need to shrink it to the size of Walkman, or else you are putting your subjects at risk of being shot.’”
Shrinking the sensor
This is just what he did with help from Cowin, who leads the hardware and software development side of the project. “The sampler is not cell phone-size yet (the 1991 models, notwithstanding) but it is pretty compact,” Cowin notes, adding how much quieter it is compared with the early, humming models.

The work in progress — currently 15 centimeters long, less than 7.5 centimeters wide, and weighing about as much as a Walkman — is undergoing validation to ensure that filters only 0.2 centimeter in diameter can really do equivalent work to the old 3.7-centimeter-wide models. The prototype houses six of these pollution nets: three for the collection of black carbon and three for single particles, both prevalent in urban air and suspected hazards for children’s health.

Each pair of filters is then designated for one of