A systematic review on status of lead pollution and toxicity in Iran; Guidance for preventive measures

Lead is an old environmental xenobiotic metal which is presented everywhere [1] and its chemical properties make a wide spectrum of applications possible for lead. Lead is used in more than 900 industries, including mining, smelting, refining, battery manufacturing and so on [2]. It is one of the most abundant natural substances [3] and is the fifth highest metal used throughout the world. In Iran, application of lead dates back to 5,000？years ago [4] and previous Iranian scientific such as Haly abba (10 th century), Rhazea (865–952 CE) knew about concept of lead poisoning. Iranian people used lead for different purposes such as facial powder, painting, and traditional tile brick glazing. Industries such as mining had not been modernly managed until 1930, thus there were many lead exposure in the workers. Lead toxicity is of the major concerns to public health due to widespread persistence of lead in the environment [5]. In the history of medicine; lead poisoning has been a well-known disease. The first article about lead poisoning was published in 1848 [4]. Although lead toxicity has been relatively controlled in industries but it is still the most common environmental toxicity in the United States of America (U. S.)[6] and it is an important health issue in countries such as Iran [7]. Over the past decades; efforts have been made to reduce its exposure [5]. The activity related to the workers safety and occupational health has been started from 1946 in Iran [4].Signs and symptoms of lead poisoning included hearing loss, anemia, renal failure, and weakened immune system, and Low birth weights, still births and miscarriages, premature births, and increased urine and blood lead levels (BLL) are the most common reports [8].BLL provides the best parameter of recent exposure to this metal [9]. Normal BLL is less than 30？μg/dL, whereas acceptable BLL ranges between 30 and 49.9？μg/dl while high BLL refers to higher than 49. 9？μg/dL [9]. The World Health Organization (WHO)