In the United States, levels of arsenic that are above natural levels, but still well below danger levels set in federal safety standards, have been detected in commercially raised chickens. The source of the arsenic appears to be the feed additives roxarsone and nitarsone, which are used to control the parasitic infection coccidiosis as well as to increase weight and skin coloring of the poultry.High levels of inorganic arsenic were reportedly found in 83 California wines in 2015. Soil
Exposure to arsenic in soil can occur through multiple pathways. Compared with the intake of naturally occurring arsenic from water and the diet, soil arsenic constitutes only a small fraction of intake. Air
The European Commission (2000) reports that levels of arsenic in air range 0–1 ng/m3 in remote areas, 0.2–1.5 ng/m3 in rural areas, 0.5–3 ng/m3 in urban areas, and up to about 50 ng/m3 in the vicinity of industrial sites. Based on these data, the European Commission (2000) estimated that in relation to food, cigarette smoking, water, and soil, air contributes less than 1% of total arsenic exposure. Pesticides
The use of lead arsenate pesticides has been effectively eliminated for over 50 years. However, because of the pesticides environmental persistence, it is estimated that millions of acres of land are still contaminated with lead arsenate residues.
A stent may be inserted to keep the newly formed airway patent. Repeated dilatation may be performed. CT guidance may be used. Epidemiology
Choanal atresia is fairly rare. It may have a frequency between 1 in 7,000 births and 1 in 5,000 births. History
Choanal atresia was first described by Roederer in 1755. Society and culture
In the movie City of Angels, Dr. Maggie Rice (played by Meg Ryan) correctly diagnoses the cause of a newborn babys failure to thrive as due to choanal atresia. References


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