The 1957 fire at the Windscale nuclear reactor in the UK caused what was at that time the world's worst nuclear accident which is conservatively expected to cause as many as 100 fatal cancers and a similar number of non-fatal ones. The report of the immediate official enquiry was not made public until 1988 for fear that Britain's allies would perceive it to be incompetent. Under its new name of Sellafield, the UK government refused in 1994 to reveal the health and environment risk assessment associated with its new role as a nuclear processing plant.
Greenpeace claimed that there was a USA cover-up over the environmental effects of the Gulf War, particularly air pollution from burning oil wells, because it counteracted the myth of a clean, smart war. Information on unusually high levels of soot in the air over Hawaii was never released because of a deliberate USA Department of Energy directive to national laboratories "to immediately discontinue any further discussion of war-related research and issues with the media until further notice".
Files kept secret for by the former Soviet Union for many years, revealed in 1994 that it had systematically slaughtered a large part of the world's protected whale populations in a systematic military style operation lasting 40 years. Thousands of whales had been killed, including entire herds and even populations which were considered protected by the International Whaling Commission (IWC). It was also revealed that Soviet whaling continued in prohibited areas, at prohibited times and up to 1993, 17 years after the former Soviet Union was allowed to whale commercially. Over 90% of the Soviet take constituted violations of IWC rules.
In 1992, an Israeli El Al cargo jet plowed into a low-income housing complex near Amsterdam in 1992, killing 43 people and injuring dozens. The cause of the crash was established fairly quickly: fatigue in a "fuse pin" on the engine mount. More than a thousand medical complaints from residents in a neighbourhood 12 kilometres east of the airport were reported, but only in 1998 it was revealed that apart from electronics, flowers and perfume, as originally claimed, the aircraft carried also DMMP (part of a combination of elements used to make sarin nerve gas) and 270 kilograms of depleted uranium, used for ballast in the tail section of the older aircraft. Incomplete and unsatisfactory answers from Israel about what the El Al freighter was carrying led to pleas of ignorance and charges of withheld facts. The cockpit voice recorder was never found, although the flight data recorder was, and a Dutch investigation concluded it had probably been stolen from the crash site. There were allegations that Israeli security personnel, who were at the site within minutes of the crash, might have taken the voice recorder. It was a mystery why, the day after the crash, El Al rushed special jets to Schiphol and what they might have airlifted out. Besides, although more than half of the uranium had been recovered, it was not known what happened with the rest.
In 1997, during the time of the large forest fires in Southeast Asia, the Malaysian government banned academics from making statements on the country's haze problem, drawing warnings about threats to freedom of speech. The directive was issued because some comments by academics on the haze problem had been manipulated by the foreign media to mar the country's image. Researchers could still publish their findings, but those related to the environment and haze had to be submitted to higher authorities for approval.