THE FEDERAL GOVERNMENT'S revelation last March that significant quantities of Mexican-grown marijuana entering the United States have been contaminated with the potentially lethal herbicide paraquat has sparked a nationwide controversy over the steps that should be taken to respond to the possible danger. Cambridge health officials and administrators took the initiative in responding to the problem and have thereby involved the city in a dispute with the state of Massachusetts over governmental jurisdiction. The city and its officials have already received a pledge from Harvard to supply technical staff to the city's proposed paraquat testing program--the bone of contention between the state and Cambridge--and the University community and Cambridge citizens should lend further support to the city in its fight with Massachusetts over the legality of the testing project.

Cambridge health officials announced last Friday that a laboratory in Cambridge City Hospital will begin testing samples of confiscated marijuana within the week, arousing the opposition of the state Public Health Department on the grounds that possession of marijuana in Massachusetts remains a criminal offense and should not be tested for "drug peddlers" seeking a "certification to sell marijuana." City officials reply that the purpose of the proposed testing is to determine how widespread contaminated marijuana is in Cambridge. The City of Cambridge has decided to appeal directly to the governor, and Dukakis should follow the lead of California by permitting the program to begin immediately. The findings of the Palo Alto, Cal. laboratory PharmChem--that 32 per cent of over 4000 pot samples tested showed signs of paraquat poisoning--should eliminate all doubts as to the legitimacy of and the need for the operation of such a program in Massachusetts.

Because state officials estimated that only 20 per cent of the marijuana in the Commonwealth is from Mexico, where the paraquat spraying occurs, the state will test for the presence of the herbicide in marijuana confiscated throughout the Commonwealth, in order to decide whether a larger paraquat testing program is necessary. Cambridge should be commended for having foresight and common sense in trying to initiate the testing program, which will occur in city police labs if and when the state approves the project.

On a broader scale, the federal government should cease all involvement in the Mexican government's herbicide war on the nation's marijuana fields. The U.S. State Department has promised to produce an environmental impact statement detailing the effects of Mexico's "drug-eradication" program on the United States; such token action remains an insufficient response to a growing problem affecting millions of marijuana users in this country. The National Organization for the Reform of Marijuana Laws (NORML) filed a lawsuit last March 13 seeking an injunction to halt the herbicide spraying program pending the publication of the environmental impact statement; we hope the federal courts will rule in NORML's favor. In the meantime, the paraquat problem is very much with us, and an end to the spraying program coupled with the launching of the city's pot testing project will represent two important steps towards dealing with this tax-dollar funded health threat.