<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by beaverjim:
fred, that was a joke about the diesel exhaust causing the black streaks
No joke Jim, health facts from the State of California. Black streaks are a black oily film.
If you spend some time in SoCal you will notice the constant heavy flow of truck traffic to and from the Port of Los Angeles. Huge amounts of particulate matter being discharged.