Although new landfills are lined to prevent leaks of toxic substances and often capture methane, the process is highly inefficient, it noted.
And once chemicals are in use, the burden on the E.P.A. is so high that it has succeeded in banning or restricting only five substances, and often only in specific applications: polychlorinated biphenyls, dioxin, hexavalent chromium, asbestos and chlorofluorocarbons.
These conditions are called lysosomal disorders after the lysosome, the structure in the cell that contains these substances, and often produce symptoms of neurological involvement at birth or in the early years of childhood.
Drilling fluid contains clay, cuttings, barite powder, and other solid substances, and often, there is a free state of the gas.
The federal government has allocated 8.4 billion Canadian dollars ($6.4 billion) over five years to aid indigenous communities, which have disproportionately high levels of poverty, incarceration, alcoholism and substance abuse, and often lack basic necessities like safe drinking water.
Beset by high rates of unemployment and poverty, elevated levels of infant mortality, diabetes, tuberculosis, and substance abuse, and often overpopulated, reservations struggle to provide a better life for residents while maintaining as much of their traditional culture as possible.
Guantánamo is seldom about substance and very often about perception and politics.
Diving into college admissions essays right away leads to flowery essays with little substance and an often desperate tone.
Previous work with an alternative strain can be used to ensure that the strain selected is responsive to a particular substance and can often negate the need for the NTP to conduct dose-finding studies.
