A sol-gel-based TiO₂-coated photo-catalytic device was developed and demonstrated for field applications for controlling volatile organic compounds (VOCs) in three varying indoor environments: (i) laboratory using benzene (efficiency >99%), (ii) conference room of an industry producing organic solvents (mono, di, and tri chloro benzene) (efficiency >70%), and (iii) chemistry laboratory using multiple solvents/VOCs (efficiency >88%). The VOC degradation rate constant for coexisting multiple VOC was estimated to be 1.06/min/m², which was about 34% less than that of benzene. A VOC mass balance model was developed to describe interaction between indoor air and kinetics of VOC degradation to estimate required extent of treatment for safe VOC concentration in the indoor air. Toxic intermediates of benzene that were adsorbed on the catalyst surface (solid phase) were identified and quantified with GC/GC-MS (gas chromatography-mass spectroscopy). Intermediates accounted for less than 5% of the total mass of benzene treated. The overall hazard index of the toxic intermediates released from regeneration of catalyst is estimated in the range 0.11–0.74, which is less than 1, and, thus, poses no significant risk to the occupants.

The global increase in industrialization and its attendant exponential air pollution has posed a significant hazard to the indoor pollution levels of cities and the associated health risks. This study evaluated the health effects of air pollutants discovered inside the bottling industries in Chandigarh cluster in India. PM_10, PM_2.5, PM₁, and black carbon concentrations in the post-monsoon season were monitored, and associated health implications and lung disease were estimated. A positive correlation is established between PM in indoor and outdoor environments. Maximum concentrations for PM₁₀, PM_2.5, and PM₁ were recorded as 276.8 µg/m³, 97.7 µg/m³ and 66.5 µg/m³ (for indoor) respectively, which are approximately 15 and 6 times higher than their (PM₁₀ and PM_2.5) allowable concentrations set by World Health Organization, posing a health threat to the workers and staff of the industries. The lifetime carcinogenic risk of black carbon and the non-carcinogenic risk of particulate matter and black carbon have been assessed using a deterministic and probabilistic model, which shows the marginal difference. The estimated lifetime carcinogenic risk due to black carbon for males and females was observed in the range of 7.20E-05 to 6.17E-05. The spirometry analysis indicates that about 13.04% of the sample population (out of 184 samples) have healthy lungs.