NSSGA，美国沙石协会。
NSSGA is the National Stone, Sand and Gravel Association. On Feb. 12, 2001, the National Stone Association and National Aggregates Association merged to become the NSSGA. The association represents the crushed stone, sand and gravel-or construction aggregates-industries. Our member companies produce more than 90 percent of the crushed stone and 70 percent of the sand and gravel consumed annually in the United States. Nearly two billion metric tons of aggregates were produced in 2010 at a value of approximately $17 billion, contributing $40 billion to the GDP of the United States. The aggregates industry workforce is made up of about 106,700 men and women. Every $1 million in aggregate sales creates 19.5 jobs, and every dollar of industry output returns $1.58 to the economy.
