Industrial air pollutants, such as organochlorines and heavy metals, are carried to the arctic on air currents from populated areas. Lichens are a dominant life form on the tundra, and they are particularly vulnerable to air pollution because they lack roots and get the majority of their resources from the air. Because of this, lichens have historically been used as air pollution indicators.
Hurst is a city in Tarrant County, Texas, United States. Hurst is one of the Mid-Cities between Fort Worth and Dallas. it is local a suburb of Fort Worth. The city was founded by William Letchworth Hurst. As of the 2010 census, it had a population of 37,337.
Houston County is a county located in the U.S. state of Texas. As of the 2010 census, the population was 23,732. Its county seat is Crockett. The county is named for Sam Houston, a president of the Republic of Texas and Governor of Texas. Houston County was one of forty-six prohibition or entirely dry counties in the state of Texas, until voters in a November 2007 special election legalized the sale of alcohol in the county.