Unadjusted and adjusted hierarchical regression model-pH effect vs die-off rate, n = 30.

Confidence Interval in parentheses; Note: p value for all the parameters was less than 0.01.A: Model Main effect, B: Adjusting for metal, C: Adjusting for incubation period (Time), D: Adjusting for metal and time, E: Adjusting for metal, time and metal*pH interaction, F: Adjusting for metal, time and time* pH interaction, G: adjusting for metal, time, metal*pH interaction and and time* pH interaction.Note: Each model includes the coefficient and their confidence interval in bracket.