Tea fields in Zhejiang

The tea fields of coastal Chinese province Zhejiang cover the hills in rows of lush, green tea bushes. The image is reminiscent of the rolling vineyards of Tuscany. And in many ways, tea is to China what wine is to the West. Pu'er tea ages just like a bottle of red, with raw Pu'er from the 1950-70s commanding as much as $20,000 a pound. And whether it's high-end "luxury" teas being exchanged through the hands of China's elite or ordinary household brands being brewed in just about every household of China, tea is an essential part of Chinese culture.

But is this tea safe to drink? A recent report from Greenpeace has uncovered the presence of illegal pesticides in some of China's most popular teas such as Methomyl and Endosulfan, the latter of which has been banned globally under the Stockholm Convention due to its toxic properties.

In December 2011 and January 2012, Greenpeace took samples from nine well-known tea companies in China. Eighteen different kinds of medium-grade tea were purchased at random, and sent to an accredited third-party laboratory for pesticide testing. Twelve of the 18 samples contained at least one pesticide banned for use on tea. Every single sample contained at least three different kinds of pesticides, and on the sample Richun's Tieguanyin 803 tea a total of 17 different kinds of pesticides was found.

One of these 17 kinds of pesticides was Endosulfan, a chemical that the U.N. Stockholm Convention in 2010 called "highly toxic to humans," with a global ban negotiated last year. The pesticide has also been identified by the U.S. EPA as a potential endocrine disruptor, while other studies suggest effects on male reproductive development.

China is the world's biggest producer of tea, and also the world's largest pesticide producer and consumer. According to China's National Bureau of Statistics, in 2009, the country's total output of pesticides reached 2.26 million tons. In recognition of this problem, China's Ministry of Agriculture last year announced its goal of reducing nationwide pesticide use in 2015 by 20 percent.

This massive pesticide use isn't just putting the health of consumers at risk; it also threatens the health of the tea planters and tea processers who come into direct contact with the chemicals. A study last year conducted on 910 pesticide applicators from two villages in southern China found that more than 8 percent suffered pesticide poisoning. This followed a 2006 WHO workshop in Beijing that also looked at how pesticide poisoning was the most common method of suicide in China, mainly due to the ready availability and accessibility of highly toxic pesticides that are otherwise banned in many developed countries. Moreover, the workshop noted that an additional 17,000 annual deaths are estimated to occur from unintentional exposure to pesticides (both ingestion and occupational exposure).

There are several reasons why China's pesticide use has reached such epic levels.

One major factor has been a response to the negative impact of climate change. Rising temperatures has helped many pests and pathogens survive the usually cold, winter months, and farmers have reacted by bumping up their pesticide application. These farmers have little in the way of training, support or knowledge of the best way to deal with these changing conditions, so their attitude has become one of "spray, baby spray."

The problem, of course, is that in the long term, applying vast amounts of pesticides may do more harm than good. "In the quick pursuit of a high yield many Chinese farmers consider pesticides as the most effective, even the only way, to cope with pest and disease. But in spraying more pesticides or using more fertilizers you upset the natural balance of the soil which can lead to more disease," says Food and Agriculture campaigner at Greenpeace, Wang Jing.

Good quality soil and clean water are the foundations of China's famed tea products, and yet these basic components are being quickly compromised. Greenpeace is therefore calling on companies to switch to eco-agriculture, which make use of methods such as intercropping, light traps, and integrated pest management. Despite the vital importance to the country's future, the Chinese government's funding for research and development of eco-agriculture is currently dwarfed thirty times by that for genetically engineered food. This is particularly risky at a time when GE is proving impotent to the rapidly changing climate-affected landscape.

Replying to the grave challenges of drastic climate change, and doing so in a way that is sustainable, will only be achieved with a combination of modern knowledge and techniques, along with a revival of the time-tested farming techniques that were once a mainstay in China's long history of eco-agriculture, extending back for thousands of years.

And even if the debate around pesticide use is put aside, the fact remains that this recent report proves that there is a large-scale use of illegal pesticides in the local tea growing industry. Seven of the tested firms sit within China's top 10 tea sellers and are brands that are either turning a blind eye or being complicit with their suppliers' illegal conduct. As with many things in China – be it the release of toxic chemicals by manufacturing companies or big brands breaking the law in regards to working conditions – it's the lack of an effective traceability and supply chain control system that time and time again sees laws being broken.

As this story of China's compromised quality control in their tea begins to spread around the world it remains to be seen whether it will have an impact of tea exports, one of the country's most important export commodities. In 2010, the country exported 302,400 tons of tea valued at $784 million.

"That more than half of China's top 10 tea sellers are selling tea tainted with banned pesticides is a huge embarrassment for China's tea industry," Wang Jing says. "It shows a totally lack of responsibility from the tea sellers, who have failed to exercise any control over pesticide usage."