True or False?

(a) The primary purpose of risk assessment is to limit chemical exposure risks to humans and ecological communities; (b) Whereas baseline or forward risk assessment quantifies the actual exposure risks attributable to chemical exposure, risk back-calculation determines allowable chemical concentrations; (c) The mean contaminant exposure concentration, such as might be represented by the 95% upper confidence limit on the population mean, is a main component of baseline risk assessment; (d) The difference between probabilistic risk assessment and conventional or point risk assessment is that the former provides the occurrence probabilities or likelihoods of specified point risks, whilethelatter produces specific point risks, forthe given exposure characteristics; (e) The exposure point concentration is required for probabilistic risk assessment, whereas the contaminant distribution characteristics such as the mean and standard deviation are used for point risk estimation; (f) Variability and uncertainty in risk assessment are essentially identical; (g) A cancer risk of 1 in 1 million guarantees atleast one cancer-related mortality attributable to chemical exposure; (h) All contaminants and chemicals have carcinogenic health effects; (i) A hazard quotient not exceeding 1 indicates minimal noncarcinogenic health effects attributable to contaminant exposure; (j) The terms hazard quotient and hazard index are synonymous.