A strangely compelling, end of world tale, that could easily have gone astray but did not, due to the intimacy of the relationships told through exquisite writing and performances. Told in a mosaic fashion that builds to create a beautiful whole, the film first intrigues and then, inch by inch, draws you in. Wonderful performances all round from veterans and newcomers alike. ( Always a sign of an excellent director.) Frank Langella, Gena Rowlands shine in the mature, understated way of older greats. Josh Hartnett also brought something special to his role, as did Rosario Dawson. But it was Theresa Palmer who brought an exquisitely luminous and fragile element to her role and really brought true soul to the whole movie. An actress well worth keeping an eye out for.A movie that transcends its not so uplifting subject matter to somehow create an uplifting movie, in a melancholy kind of way. Welll worth a deeper look.

I kept watching thinking surely this movie would develop and do something other than bad mush. The bubble gum philosophy was mangled to the point it begged to be put out of it's misery. The acting was first rate but the script doesn't even move enough to be coherent or incoherent. It just lays there softly whimpering and perhaps whimpering is too strong a word. It would be impossible to write a spoiler for this movie since something would need to happen to spoil. What a waste of a great cast. Give me a week and I could write something considerably better than this. Even the romantic angle was bled out so painfully slow with so many pointless interruptions that it does not even rate up with a trashy romance novel. Save your eyes, mind and any other organs you wish to spare the agony of enduring this movie.

A film I couldn't wait to end it was so slow and non eventful. The script was minimal,there were no noticeable transitions to the flashbacks and most of the characters acted as if they had no idea what was happening.This was an example of good well known actors roped into what was supposed to be a modern day version of On the Beach, but without any of the tension, dialog and story. Rather than engaging in pointless flashbacks, more attention should have been paid to the worldwide disaster unfolding.Parts Per Billion illustrates why many low budget films never get shown widely...the script was lousy and production values mediocre.

I watch 2 or 3 movies per day in my free time and this was probably the worst movie I have seen in over a year.. Movie was extremely suspenseful, but the end just died out and left you hanging.. Was extreme waste of resources and time. I thought josh hartnett scenes were really good but you don't even know what happens to him and his wife at the end.. Also would have liked to seen what happened to the old couple. Also don't know if the black guy dies because the bikers could have shot each other or someone could have shot them through the window. Everyone wants to know an ending so producers should put them in every movie