It is hereby declared that insanitary or unsafe dwelling accommodations exist in various areas of the State, and that consequently many persons of low income are forced to reside in such dwelling accommodations; that these conditions cause an increase in and spread of disease and crime and constitute a menace to the health, safety, morals and welfare of the citizens of the State and impair economic values; that the clearance, replanning and reconstruction of  the areas in which insanitary or unsafe housing conditions exist and the providing of safe and sanitary dwelling accommodations for persons of low income are public uses and purposes for which private property may be acquired; that it is in the public interest that work on such projects be instituted as soon as possible in order to relieve unemployment which now constitutes an emergency; and the necessity in the public interest for the provisions hereinafter enacted, is hereby declared as a matter of legislative determination. (1935, c. 408, s. 1.)