The presence of Hg in natural gas and gas condensate is termed as a “critical severity risk”, according to health and safety regulation of the petroleum industry. Mercury affects the gas processing plants as well as refinery industries; damaging heat exchanger, poisoning the catalysts and increases the exposure risk to the field workers. Consequently, in order to establish a data base project to assess both the total mercury content and/or the dominants species for certain production field, alongside with mercury distribution within a natural gas processing plant or petrochemical industries, it is vital to develop and establish a reliable, low cost, time saving and applicable method(s) to be used in oil and gas industry as a routine method, if possible. Hence, the current study primarily aimed to follow the distribution of mercury, as a total and species, within Obaiyed plant (Egypt) as a model of natural gas processing factory. Then the second phase of this work has been devoted to conduct an environmental visibility study to develop reliable and convenient methods to measure and speciate mercury on polluted crops due to industrial waste. This part of study was followed by a screening analysis for commercial rice samples represent the product of different world regions including Egypt.