U.S. researchers have developed the first \"lab on a chip\" sensor that can quickly detect levels of heavy metals such as manganese in humans, a report says.Developed by University of Cincinnati scientists, the sensor will have its first field test in Marietta, Ohio, where another UC researcher is leading a long-term health study on the potential health effects of heavy metals, a UC release said Friday.Because the sensor\'s working electrode is made of bismuth instead of the more usual mercury, it is environmentally friendly. Ian Papautsky, a UC professor of electrical and computer engineering, said the new sensor is also child friendly, requiring only a drop or two of blood, and returns results quickly.\"The conventional methods for measuring manganese levels in blood currently requires about 5 milliliters of whole blood sent to a lab, with results back in 48 hours,\" he said.For a clinician monitoring health effects by measuring these levels in a patient\'s blood -- where a small level of manganese is normal and necessary for metabolic functions -- you want an answer much more quickly about exposure levels, especially in a rural, high-risk area where access to a certified metals lab is limited.\"Our sensor will only require about two droplets of blood serum and will provide results in about 55 minutes. It\'s portable and usable anywhere.\"The sensor will be field tested by UC\'s Erin Haynes, who is studying air pollution and the health effects of manganese and lead in Marietta, the home to the only manganese refinery in the United States and Canada.Tests have revealed elevated levels of manganese in Marietta residents when compared to those who live in other cities.