Air Pollution Tolerance Indices (APTI) of Some Edible Plants Exposed to Industrial Effluents at Nnewi in Anambra State, Nigeria

Abstract: Air pollution tolerance indices (APTI) were analysed in 2 plants (Telfairia occidentalis and Ocimium gratissimum) growing on farm sites surrounding three industries: Lead-acid battery factory (experimental site 1), Petroleum products factory (experimental site 2) and PVC Pipes and Cement packaging factory (experimental site 3) with a non industrial site selected as control site all in Nnewi, Nigeria. Leaf relative water content, Ascorbic acid, Total chlorophyll and Leaf extract pH were analysed and used to calculate the APTI values. The two plants growing in experimental (polluted) sites had significantly higher (p< 0.05) APTI than those in the control site with their APTI values ranging from (8.05 to 11.20) in experimental sites and (7.83 to10.00) in control site. Both plants were found to be sensitive to air pollution with Ocimium gratissimum being the more sensitive specie with a higher percentage APTI increase (33.07±13.80%) in the experimental sites. Consumption of both plants from polluted sites may be deleterious to health with T. occidentalis being more harmful because it accumulates more pollutants. Higher APTI values with a corresponding reduced Total chlorophyll composition (p<0.05) recorded for both plants in experimental site 1suggests that effluents from Lead-acid battery factory have more hazardous effect on edible plants