"if the battery in a mechanical mod over-discharges and the device doesn't contain enough air holes to allow the battery to vent, there is a risk of explosion.".

in particular, the country has extreme levels of nitrogen dioxide due to heavily congested roads in urban areas,. tusk made his remarks about the u.s. president's reliability before he chaired a meeting in bulgaria of the 28 leaders whose countries make up the world's biggest trading bloc..