Dallas County, Texas begins aerial spraying to combat West Nile.

ABC World News (8/17, lead story, 2:15, Sawyer) opened Friday evening by reporting on the West Nile virus outbreak in Dallas, where planes were set to spray "chemicals on backyards, playgrounds, churches, as more than two million people move inside to wait and see if this works." ABC (Owens) added, "Crews spent the day after hosing down playground equipment and wiping off drinking fountains. After a night of pesticides raining down on Dallas, there's no such thing as too careful."

        The CBS Evening News (8/17, story 4, 1:55, Schieffer) said "a surge in the mosquito population is spreading this virus coast to coast and nowhere is the problem greater than in Texas where they've had 21 deaths. Nearly half around Dallas, where they've had a total of 242 cases of West Nile."

        HealthDay (8/18, Gardner) reported that before aerial spraying began, "Dallas mayor Mike Rawlings declared a state of emergency." So far, "Dallas County has recorded 10 deaths and hundreds of cases of the mosquito-borne illness."

        The Los Angeles Times (8/18, Hennessy-Fiske) reported that planes outfitted for aerial spraying of pesticides in Texas to help combat a West Nile virus outbreak were grounded Saturday by rain. Dallas County has declared a state of emergency in the outbreak, which has caused 242 cases and 10 deaths. The CDC said the Texas overall "has reported 552 cases and 21 deaths, by far the highest tally nationwide."

        CDC's Nasci says "No detectable adverse effects" from spraying. On its website, NPR (8/19, Neuman) reported, "The recent outbreak of West Nile virus in the Dallas area has led to a new round of large-scale spraying for mosquitoes." Even though "the overall mosquito-killing strategy has changed little since the days when it was pioneered during construction of the Panama Canal a century ago, the chemicals used have become much safer for everything and everyone involved, save the mosquitoes, experts say." Roger Nasci, chief of arboviral diseases at the Centers for Disease Control and Prevention, explained that the "pesticide being deployed in Dallas is a synthetic pyrethroid, an extract from dried chrysanthemum flowers. 'Nothing's perfectly safe, but there are no detectable adverse effects,' he" stated.