  == Relief and Social Services ==  Added source reference and updated.   Pared away following details, but kept the 6% figure in the text:  Fewer than six percent of refugees qualify as hardship cases, with the largest number being in Lebanon where restrictions on Palestinians entering the Lebanese job market cause severe hardship.  Rations are distributed to families in UNRWA's special hardship category every quarter.  Finances permitting, the Agency also provides small cash grants to very poor refugee families to help with the purchase of items such as school uniforms and school books or as crisis grants, for example if they lose all their possessions in a house fire.  Most of the concrete-block shelters in the refugee camps were built by UNRWA in the 1950s to replace the tents in which refugees had lived since the 1948 war. Others were built after the 1967 conflict. Although most refugees have been able to make improvements and additions to their shelters over the years, the very poorest refugees often live in shelters that are now in extremely bad condition. Wet, crumbling walls, leaking zinc roofs and rodent infestation cause additional social and health problems. UNRWA has been able to repair hundreds of shelters in recent years, often simply by supplying materials while the families provide their own labour. UNRWA is unable to keep up with the growing numbers of special hardship case families who each year join its waiting list for shelter rehabilitation.    