ABSTRACT
Exposure to inorganic arsenic mainly occurs via drinking water, however because of potential changing of water sources during time, there is not consensus over the best route for assessment of past exposures to arsenic. At present study, we compared three potential sources of data in this regard. Thirty nine human hair samples were taken from persons residing in three villages of Bijar city in Kurdistan province of Iran with different drinking water sources and different levels of arsenic. All the subjects were female and at least one gram of scalp hair was gathered from the distal part of participants hair. Samples were analyzed using Neutron Activation Analysis method. Arsenic concentration of water samples were measured using Silver Diethyl Ditiocarbomate Method [SDDC] and the total intake of arsenic through drinking water were calculated for each participant. According to results, arsenic content of drinking water ranged from 0 to 0.455 mg/I [average: 0.18]. The figures for arsenic concentration in hair were from 0.012 to 3.41 mg/kg [average: of 0.53] and for calculated total intake from 0 to 8.9g [average: 2.02]. A close relationship between calculated total intake via drinking water and arsenic concentration in hair [R.711, P<0.001] was obtained and also relationship between current arsenic content of drinking water and arsenic concentration in hair [It= 0.662, p<0.001]. Using age as a co-variate did not alter the results
ABSTRACT
Sludge production is an avoidable problem arising from the treatment of wastewater. The sludge remained after municipal wastewater treatment contains considerable amounts of various contaminants and if is not properly handled and disposed, it may produce extensive health hazards. On the other hand, this sludge has benefits for plants and soils. Thereupon, land application of sludge has received much attention over the traditional incineration and dump in sea. The comprehensive regulations of U.S.EPA title 40 CFR parts 503 include criteria and standards for land application of sludge. One of the most important wastewater treatment plants in Tehran, Iran is Shoosh Plant, which applies its waste sludge in agricultural lands after dewatering in drying beds. In this research, waste sludge from drying beds was examined according to 40 CFR parts 503. Results indicate that the dehydrated sludge has not the characteristics required for final discharge. If the dewatering process in the existing beds of the plant would be modified according to title 40 CFR part 503, the standard of Pathogen Reduction class B would be achieved. Waste sludge of drying bed must be applied in agricultural land with respect to the conditions of application method that is presented in vector attraction reduction. Concentration of this waste sludge is less than ceiling concentration limits identified by title 40 CFR parts 503