Tea fields in China

We all know the health benefits of tea, and in most cases there are few side effects unless you drink in extreme quantities. Heavy metal exposure, though, can lead to a number of problems, especially with young children. Lead poisoning from paint chips is probably the most well-known, since it is present in older homes.

When it comes to contamination, tea is no different than many other foods. Much of the contamination is from the soil and air. The problem is that China has a known reputation for pollution, as evidenced by the massive smog that envelopes Beijing every year. While they are taking steps to reduce pollution, it is still a massive problem. But let’s be clear, China is not the only country with pollution problems. Some of the Chinese emissions also make their way across the ocean along the west coast of the US, contributing to west coast air quality problems as well as finding its way into oceans and contaminating fish.


You might think this can be solved by going organic. In the case of heavy metals, being organic has little to no effect. A few years back, consumer reports revealed high levels of arsenic in USA grown organic brown rice. In this case the rice leached heavy metals from the soil that was from activity decades prior. Heavy metals can find their way into tea in the same way, and pretty much into any other food product regardless of organic status.

A few examples:

” […] researchers conducted an analysis of wheat grown on various farms in Belgium; based on the results, they estimate that consumers of organically grown wheat take in more than twice as much lead, slightly more cadmium, and nearly equivalent levels of mercury as consumers of wheat grown on conventional farms. “

“[…] 14 percent to 28 percent of New Zealand’s cattle (destined to be organic beef) were found to have kidney cadmium levels exceeding limits set by the New Zealand Department of Health because of a diet of plants grown in contaminated soil. Similarly, a 2007 study of Greek produce found that organic agriculture does not necessarily reduce the cadmium and lead levels in crops. As it turned out, “certified” organic cereals, leafy greens, pulses, and alcoholic beverages had slightly less heavy-metal contamination than conventional products, but “uncertified” organic products had “far larger concentrations” than conventional ones.”


Contamination of tea can occur by a variety of industrial activity. A big source is coal fired power plans.

It is interesting to note that India, as of 2013, derives 44% of its power from coal, biomass 23% and the nuclear, hydroelectric and renewables only 4 percent combined. China on the other hand, gets 57% from coal, while hydro, wind, solar and nuclear make up over 35% combined. So while net, China uses more coal, their “clean” energy percentage is much higher than India. Nuclear energy is expected to overtake the U.S. in 10 years, with 21 nuclear plants under construction with more planned – mainly to reduce the emissions from coal.  But, for the time being, coal is king.


These are two recent studies that talk about tea:




“It can be explained by the variations in Lead contamination sources of anthropogenic provenance, i.e., batteries, paints, dyes, and heavy industries. Moreover, Souza (2005) implied that 96 % of lead in the atmosphere is of anthropogenic origin.”

What does the above statement mean? Most of the lead in the atmosphere is caused by human activity. China is a large country, but not all of the country is mired in smog or near coal plants. There are many areas that are not polluted, or have nearby topography that blocks pollution from other areas.

7 of the 10 most polluted urban areas in the United States are in California. This does not mean that all California produce and wine should be ruled out (there are studies about heavy metals in wine).

The one thing that I did find is that you can find a study with negative information about almost everything. It will make you want to pull your hair out! 

One report said China acknowledged that 1/5 of its arable land was contaminated. But it doesn’t really provide much in the way of tea production. I did find a specific study in a region which is a big tea producer:

Heavy Metal Pollution in Zhejiang Provence

Their conclusion

“160 samples were in the safety domain, 12 samples in the precaution domain and only 7 samples were slightly polluted. According to the assessment map of tea soil environmental quality, up to 93% of the study area was belonged to safety domain, 6.5% belonged to the precaution domain, whereas only 0.50% area was slightly polluted domain.”


The first tea studies I referenced have a few things to point out:

“A limitation of this study is that this is a sample of convenience using samples readily available in supermarkets and health food stores in Canada.”

“They were purchased from various tea shops (tea of certified origin) and markets (marketed tea)”.

The first study uses samples found in supermarkets and health food stores. These are not reliable sources of tea. Why? Because big mega brands don’t always source a particular tea from the same plantation. For example, a big mega brand uses a blend of different teas from massive pallets to make their signature tea. Their blender uses his taste buds and a computer to fine tune the formula. Because their blends are measured in tons, it’s pretty hard to determine where exactly the tea comes from.

The second study is a little more reliable in that it uses tea shops as part of its source. Many smaller tea shops don’t purchase from mega distributors and often they will get tea from single source origins. But some mega brands are also on the list, so we don’t know how specific their sourcing methods are.

Here is the main thing when it comes to tea – the higher the elevation, the further away from pollutants and contaminants. Most high end loose tea is grown at higher elevation. Many teas, even non-organic, don’t require pesticides. Cheaper tea, especially in China, is more likely to be grown at lower elevations or nearer to industrial areas. 


We can talk about contamination all we want, but is there any study that actually links tea consumption, or food consumption for that matter, to toxic side effects? We have situations like the minmato incident in Japan where a factory polluted the waters which resulted in people eating highly contaminated seafood many thousands of times beyond what is considered safe. This didn’t mean all Japanese seafood was off limits, just that particular area.

But as for casual exposure, that is very hard to track. Autism, for example, might have roots in heavy metal exposure. But there is no way to know exactly. You might avoid a product from one area, only to get something from another product you thought was safe. Or it could be your zip code. 

But as my research indicates, there is no uniform method for really finding out how much heavy metal exposure you are getting from food. There are a lot of causal relationships, but it’s hard to find any sort of evidence that eating certain foods resulted in specific symptoms.  Saying ‘all tea from China should be avoided’ just doesn’t have enough evidence to support. 

Discover magazine made a good point:

” Unfortunately, eliminating the source isn’t possible for most other pollutants that we breathe, eat, drink, and absorb through our skin whether we want to or not, including man-made chemicals such as phthalates and perfluorooctanoic acids, which are found in Teflon and other widespread products. The basic chemistry of these and thousands of other manufactured compounds incorporated in everyday products do not appear in nature; they have entered our environment so recently that our genes, cells, brains, and bodies have not yet evolved mechanisms for coping with them.”


People are getting more educated and have access to more information than ever before. Not all of it is actionable. I had a piece of tuna recently that had a stamp on it with a number where you could track its origin. I plugged it in and it actually showed where the fish was caught and a picture of the fishermen. Pretty cool. But apart from making me feel good, it didn’t say how many parts per million of mercury it contained.

Think of investing – you can find all sorts of good news/bad news on Yahoo finance. The authors are paid to make up some sort of story that fits what’s going on with the markets. You’d go broke if you bought and sold stock based on reading these articles. The same goes with health articles. The amount of “avoid this, eat that” is overwhelming. In reality, common sense and moderation are probably your best bet. 


Going through a purveyor that knows what they are doing is a must. Most of the network of importers that supply the smaller tea businesses are responsible and reputable. They provide lots of information about tea sourcing and most of them test the tea farms they do business with on a regular basis. Any good tea farm will also be registered for the FDA and other 3rd party western organizations that do independent verification. It’s in their best interest – customers demand better tea, and better tea will have superior taste (somehow I doubt a polluted tea will taste as good) and command higher prices. 

The larger the company, and especially if you are dealing with national grocery chains, tea becomes more obscure. Tea can be mixed with other tea, bundled in huge pallets and otherwise not traceable to a particular source. 

If you drink tea a lot, avoid grocery stores and buy from non-mass market tea companies. Good companies will have details and will be able to provide credentials if asked. Ask questions if you get hooked on a specific tea.


Never put all your eggs in one basket. It’s probably prudent to mix your teas up – and not just drink one type, even if it’s “safe” in heavy quantities. Rotate your selections and sources and drink in moderation. It is my opinion that the health benefits of drinking quality tea far outweigh contamination risks.


Being selective with tea from China (and in general) will help mitigate the risks of contamination. Currently, there is not enough evidence to suggest avoiding all Chinese tea. Based on the studies, be selective and opt for the higher grown varieties of tea.

What are your thoughts? Have you changed tea drinking habits based on bad publicity? Do you scrutinize other food? 

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