Up to 80% of US street meth now originates in Mexico where the crisis has been rooted since mid-2003, much of it in the far purer and more highly addictive form of "ice".

That was the year Mexican drug lords in the border town of Tijuana moved their meth factories north to start churning out cheap supplies to California, funneling it throughout the States along established drug routes like Interstate 5, the main motorway north to the Canadian border. Mexican drug cartels are illicitly obtaining tons of pseudoephedrine and manufacturing the drug in so-called "super labs". Imports of the substance in cold medicines have jumped from 66 to 224 tons in the past five years – roughly double what Mexico needs to meet the legitimate demands of cold and allergy sufferers.

The other 20% is manufactured domestically, but due to the toxicity, combustibility and noxious vapour of meth's raw ingredients, production is most prevalent in arid and sparsely populated areas such as desert territory around Palm Springs in California, Florida and the Midwest, where seizures of clandestine labs have soared in recent years. Nationally, authorities have dismantled more than 50,000 meth labs since 2001: around 30% in homes inhabited by children, the rest mostly in hotel rooms and transportable "rolling labs" such as car boots and trailers. Missouri is the most meth-plagued state with 8000 labs, equipment caches and toxic dumps seized between 2002-04. Crime units across the Midwest are swamped with thousands of meth subpoenas. In Kentucky alone, officials have worked around the clock to reduce a 10,000-case backlog.

In Illinois, police have created six teams of 56 troopers dedicated to stopping the spread of dangerously volatile meth labs throughout the state. Chicago, a major transportation hub for the Midwest connecting both the east and west coasts, netted its largest ever haul of methamphetamine in 2005; 35kg manufactured in a "super lab" with a street value of $10 million.

Each pound of meth produced leaves behind up to ten pounds of toxic waste. 

Some disused labs are rigged to explode on discovery, and the clearing up of exploded sites is particularly hazardous. The FBI claims that three people on average are killed each year by explosions or toxic poisoning, with countless injuries arising from lab fires. However, between 2000-4 nine child deaths alone are known to have been linked to meth lab accidents, while scores of children have been injured and thousands exposed to the drug and its byproducts. 

The Drug Enforcement Administration records that children were present at 20% of all meth lab busts last year, while a study by the National Conference of State Legislatures found that 10% of child users were introduced to meth by their parents or other family members. Babies born to meth-addicted mothers often test positive for the drug, and a single prenatal dose of meth may be enough to cause long-term neurodevelopmental problems in babies, according to researchers at the University of Toronto.

In 2001, law enforcement in Rice County, Kansas, pioneered a program called Meth Watch, educating local retailers, mail carriers, meter readers, road maintenance workers, teachers and civic organisation officials about the dangers of meth and how to spot potential labs. Meth Watch resulted in tip-offs leading to numerous meth busts and a decline in local meth labs, and succeeded because the involvement of the entire community played on the paranoia of the local meth producers, most of whom were users. "It's hard to appreciate how paranoid these individuals really are," said Rice County's Sheriff Bundy. "I've been in this business 20 years and never seen anything like it." Rice County's success has been replicated in communities in more than a dozen states.

In the US Pacific state of Hawaii, where around half of all men arrested and screened for drugs test positive for ice, the University of Hawaii psychiatry department estimates that between 10-15% of the tourism-based state's 1.25 million population are users, driven to meth by increasing social deprivation and poverty. In 2005, Honolulu's chief medical examiner attributed 85 deaths to meth, a 27% increase on the previous year.