Air pollution is a major cause of environmental health problems with devastating effects all over the world. In recent years, new techniques of air sampling have been developed for the assessment of air pollutants. In this study, a simplified technique based on the US EPA Test Method 26/26A is developed to quantify the concentration of Chlorine (Cl₂) and Hydrogen chloride (HCl) in indoor air. The collection of acid gases is compared by liquid absorption between impingers and the chemically-treated filter. Results show that there is a linear relationship between the concentration of the acid gases collected and their flow rates in both cases. The chemically-treated filter method is found to quantify both Cl₂ and HCl to a certain sensitivity compared to the impinger method. Errors are inherent in the measurement system. Although the uncertainties cannot be reduced to zero, by quality assurance study, the new methods are viable. Small-sized apparatus, portable, simple to operate and exclusiveness of any volatility are some of the advantages of the developed filter. It is also shown that chemical reaction of Cl₂ with Sodium hydroxide (NaOH), and HCl with Sulphuric acid (H₂SO₄), produced ion chlorides that can be determined instrumentally.

Quantitative data are needed to study the sources, behavior and effects of contaminants to the environment which eventually enable the setting up of quality standards evolvement with abatement techniques, building of predictive models of analysis and stressing the need to abide by regulatory laws. Harrison (1992) and IPCS (1982) reported that there is a significant growth in the number of air polluting substances including Chlorine (Cl₂) and Hydrogen chloride (HCl) produced by chemical industries. These gases are considered poisonous at certain concentrations (measured in parts per million-ppm). Air polluted with these gases is a threat to our health and environment as well. The report further indicated that Cl₂ and HCl at low concentrations are irritating and corrosive to the eyes, skin, mucous membranes and upper respiratory tract of human beings. As concentrations increase, symptoms become more severe and involve more distal portions of the respiratory tract. The report concluded that exposures to high concentration may cause lung congestion, pulmonary oedema, pneumonia and bronchitis. Thus, the sources of Cl₂ and HCl need to be verified and monitored (MSDS, 2003 and 2008). Chlorine and HCl are found in many industrial applications, including petroleum refining operations, like solvent intermediates for polyvinyl chloride and polyglycols. Besides, Cl₂ is used in the disinfection of wastewater bleaching of pulp and paper (Richard and Ronald, 2001; and Soo, 2002).

Hydrogen chloride emerges as a by-product of hydrocarbon chlorination and dehydrochlorinations. Most of it is consumed by the chemical industry. Large quantities are used in pickling of steel. Acidification of oil wells for the increase of flow is becoming popular. Small amounts are used for the adjustment of pH in wastewater treatment (IPCS, 1982).

Environmental Sciences Journal, Hydrogen Chloride, Quantitative Data, Pulmonary Oedema, Industrial Applications, Hydrocarbon Chlorination, Dehydrochlorinations, Chemical Industry, Wastewater Treatment, UV Spectrophotometry, Gas Chromatography, Pollution Control Processes, Glass Mircofibre Filters,Impinger Method.