▁sed iment ation ▁event ▁itself ▁might ▁be ▁relatively ▁short - l ived , ▁the ▁e colog ical ▁dis ruption ▁caused ▁by ▁the ▁mass ▁die ▁off ▁often ▁pers ists ▁long ▁into ▁the ▁future . ▁ ▁One ▁of ▁the ▁most ▁serious ▁and ▁long - running ▁water ▁er os ion ▁problems ▁world wide ▁is ▁in ▁the ▁People ' s ▁Republic ▁of ▁China , ▁on ▁the ▁middle ▁reaches ▁of ▁the ▁Y ellow ▁River ▁and ▁the ▁upper ▁reaches ▁of ▁the ▁Yang t ze ▁River . ▁From ▁the ▁Y ellow ▁River , ▁over ▁ 1 . 6 ▁billion ▁tons ▁of ▁sed iment ▁flows ▁into ▁the ▁ocean ▁each ▁year . ▁The ▁sed iment ▁origin ates ▁primarily ▁from ▁water ▁er os ion ▁in ▁the ▁Lo ess ▁Pl ate au ▁region ▁of ▁the ▁north west . ▁ ▁Air bor ne ▁dust ▁poll ution ▁So il ▁particles ▁picked ▁up ▁during ▁wind ▁er os ion ▁of ▁soil ▁are ▁a ▁major ▁source ▁of ▁air ▁poll ution , ▁in ▁the ▁form ▁of ▁air bor ne ▁particul ates — " d ust ". ▁These ▁air bor ne ▁soil ▁particles ▁are ▁often ▁cont amin ated ▁with ▁to xic ▁chemical s ▁such ▁as ▁p estic ides ▁or ▁pet role um ▁fu els , ▁pos ing ▁e colog ical ▁and ▁public ▁health ▁ha z ards ▁when ▁they ▁later ▁land , ▁or ▁are ▁in h aled / ing ested . ▁ ▁D ust ▁from ▁er os ion ▁acts ▁to ▁suppress ▁ra inf all ▁and ▁changes ▁the ▁sky ▁color ▁from ▁blue ▁to ▁white , ▁which ▁leads ▁to ▁an ▁increase ▁in ▁red ▁sun