In this paper, environmental productivity variation is analysed through the pollution-adjusted Malmquist and Hicks-Moorsteen productivity indices. These productivity indices are defined as combination of multiplicative pollution-adjusted distance functions. Non convex pollution-generating technology is assumed to estimate the pollution-adjusted Malmquist and Hicks-Moorsteen productivity measures. The main sources of the pollution-adjusted productivity change are displayed. An empirical illustration is provided by considering a sample of 20 Ecuadorian oil companies over the period 2012-2018. The results are estimated through a non parametric analytic framework.