Sentence:  The notion of toxicity is a useful one in our effort to understand the further implications of Pluto in the USA chart. [...] Factor in what we have learned about the second house and we get another meaning of "waste", related but distinctly more <WSD>Plutonian</WSD>: debris that poses an elimination problem once its value has been used up. 
Meaning of the word marked with <WSD> tags:  Pertaining to the astrological influence of Pluto, formerly regarded as a planet.