In this study, we investigated the atmospheric heavy metal concentrations in the particulate matter inside the subway stations of Seoul. In particular, we examined the correlation between the heavy metals and studied the effect of the heavy metals on cell proliferation. In six selected subway stations in Seoul, particulate matter was captured at the platforms and 11 types of heavy metals were a...

A Zigbee-based ubiquitous sensor network (USN) has many industrial applications and provides flexible measuring environments. In particular, the USN system can replace existing measuring devices in harsh environments such as subway stations. To monitor the intensities of various pollutants and air qualities in subway tunnels, this study applied the USN technique. A novel wireless sensor module,...

Modeling and analysis of a subway fire emergency response processes are extremely important in metro operation. In this study, a Petri net based approach is proposed to model and analyze the time and resource issues of subway fire emergency response processes. More specifically, the formal specification of subway fire emergency response process is first defined and a real subway fire response p...

A prior study in New York City observed that airborne concentrations of three metals found in steel - iron, manganese, and chromium - are more than 100 times higher in the subway system than in aboveground air. To investigate the potential for health effects of exposure at these levels, we conducted a pilot study of subway workers comparing personal exposures to steel dust with biomarkers of me...

BACKGROUND Obesity is an epidemic in the United States. Two-thirds of the population is overweight and does not get enough exercise. Eastern cities are full of escalators that transport obese Americans to and from the subway. Walking stairs is a moderate activity requiring 3-6 metabolic equivalent tasks (METS) and burning 3.5-7 kcal/min. We determined the caloric expenditure and potential weigh...

The panoply of microorganisms and other species present in our environment influence human health and disease, especially in cities, but have not been profiled with metagenomics at a city-wide scale. We sequenced DNA from surfaces across the entire New York City (NYC) subway system, the Gowanus Canal, and public parks. Nearly half of the DNA (48%) does not match any known organism; identified o...