value of avoided rework and increased efficiencies produced by the engineers' planning is a balance of resource utilization on any large project. Union laborer often earn more than nonunion and can be an avenue for those who are uneducated and with no resources to become educated and with resources. Hazards and conditions There are dangers associated with laboring. Many laborers are severely injured or killed in accidents each year while performing work duties. Many who work as laborers for even a short period of time will suffer from permanent work injuries such as: hearing loss, arthritis, osteoarthritis, back injuries, eye injury, head injury, chemical burn (lime sensitivity), lung disease, missing fingernails and skin scars. Alcoholism, drug use, and drug abuse are common although most companies require drug screening for all new hires. If a laborer is injured on the job they are immediately given a drug test. If the test results are positive then they are ineligible for any Workers' compensation benefits. There is a gray area for the use of marijuana due to medical marijuana prescriptions. Some who have been dismissed for failing a drug test while possessing a prescription have been later reinstated with pay as having been wrongfully terminated. Collective bargaining The Laborers' International Union of North America (LIUNA) represents laborers on public and private projects in North America. Some of the business representatives are laborers who have been so severely injured they can no longer labor. With a phone call and a good reason they will be on-site the next morning asking questions and demanding apologies for mistreatment of laborers. Images See also Hard hat, nickname for construction workers Navvy, particularly applied to describe the manual laborers working on British major civil engineering projects Working class Tradesman References Builders' labourers' trade unions Construction and extraction occupations Production occupations