As pure nylon hosiery was sold in a wider market, problems became apparent. Nylon stockings were found to be fragile, in the sense that the thread often tended to unravel lengthwise, creating 'runs'.[1]:101 People also reported that pure nylon textiles could be uncomfortable due to nylon's lack of absorbency.[31] Moisture stayed inside the fabric near the skin under hot or moist conditions instead of being "wicked" away.[32] Nylon fabric could also be itchy, and tended to cling and sometimes spark as a result of static electrical charge built up by friction.[33][34] Also, under some conditions stockings could decompose[6] turning back into nylon's original components of air, coal, and water. Scientists explained this as a result of air pollution, attributing it to London smog in 1952, as well as poor air quality in New York and Los Angeles.[35][36][37]