agriculturallaborers azcapotzalco basicchristiancommunities biography congresses economicconditions europe history industrialhygiene industrialsafety industrialworkersoftheworld jews laborunions mexico petroleum petroleumindustryandtrade politicalactivity safetymeasures socialaspects socialconditions socialmovements standards tabasco(state) unemployed unitedstates veracruz(state) wa485o1471985