Waste-water drug analysis scheme flushed with success
drug use usually peaks on weekends, that Swedes and Finns prefer amphetamines and methamphetamines rather than heroin, that marijuana and cocaine are the favoured drugs in Zagreb, that cocaine is more widely used in Oregon cities than in country areas, that far more drugs are used in Europe, China and Hong Kong than in South Korea, that university students in Washington swallow plenty of amphetamine pep pills in times of stress but consumption goes through the roof during finals exams.
In Queensland, all wastewater from an annual six-day music festival was tested for drugs. Chemists found that little amphetamine was used on the first day but usage shot from 49 to 690 units on the last day of the festival.
Colossal amounts of cocaine are dissolved in the wastewater of Medellin, Colombia, home of drug lord Escobar.
Valuable information for law enforcement has been gathered by checking waste-water in Switzerland. Sifting through sewage from two cities over two years enabled police to target a number of local dealers, gave authorities an insight into the structure of drug markets, the criminals who controlled them and how effective police operations were in limiting supplies.
Until recently, authorities checked on drug use by questioning users or suppliers but it was impossible to know if these informants were telling the truth. Though they may lie, their urine doesn’t. What about New Zealand? We are lucky in having a world expert on drug trends, drug markets, drugs and crime, and drug policy at Massey University. There, Dr Christopher Wilkins has written three books on these topics and helped set up our Illicit Drug Monitoring System.
Together with Australian colleagues, Wilkins recently tested waste-water for cocaine, methamphetamine, ecstasy and codeine excreted by 1.3 million Aucklanders.
In Christchurch, police plan to analyse the city’s waste-water over the next 12 months. They will test for LSD, marijuana, cocaine, ecstasy, heroin and other mindbending drugs, but also any new kinds of drugs that might appear. Among many other things, results should enable experts to calculate drug usage per 1000 Christchurch citizens.
Until 2005, no scientists thought to test sewage for traces of drugs. But since then, the technique has become widely used and generated vast scientific literature. One specialist says the field has ‘‘gone nuts’’.
This is my 800th science column. I usually prevail upon experts to check my columns before filing them with the paper and would like to thank a host of professors, astronomers, doctors, engineers, beekeepers, lawyers, farmers, midwives, musicians, policemen etc for spotting all those errors or inaccuracies in my drafts. I must also thank the many readers who gave me useful leads or gee-whiz stories. Bob.brockie@icloud.com
A: Associate Professor Merilyn Hibma, of the department of pathology at the University of Otago, responds:
Cervical cancer may occur when there is a long-term infection with human papillomavirus (HPV).
There are many types of HPV that infect our skin. It is only when the infection is with a ‘‘cancercausing’’ HPV, and when the infection is not cleared by our body’s immune system, that there is a risk of cancer developing.
The HPV infection causes changes to the cells of the cervix that can be detected by the ‘‘pap’’ smear. These changes indicate a greater risk that cancer could occur and, depending on the type of change, are monitored or treated.
The HPV vaccine protects against the two major cancercausing virus types – 16 and 18. Vaccination should be administered prior to sexual activity and works best in younger women.
The vaccine is very effective for the two cancer-causing types, but vaccinated women are still at risk of infection with other types. Also, the vaccination rates in New Zealand are relatively low, and unvaccinated women are particularly at risk of developing cellular changes that may lead to cancer.
The Ministry of Health is planning to use a new test that identifies HPV DNA in the future. This test is very sensitive for detecting HPV, but a positive test is not always associated with cellular changes or persistent infection, particularly in women under 25.
By commencing screening after 25 years of age, the risk of unnecessary treatment in young women is reduced.
An effective screening programme to prevent cervical cancer requires participation.
With good participation in screening by women, this change in age of commencement of screening will not reduce the effectiveness of the screening programme in New Zealand.
Source - Science Media Centre