Tea contains a number of bioactive chemicals that contribute to health, however, can contain a number of hazardous substances including plastic that present public health risk.
Tea is rich in catechins, particularly the antioxidant epigallocatechin gallate (EGCG). (1) These antioxidant properties are beneficial to prevent various diseases associated with increased oxidative stress including obesity and ageing. (2) Tea however, can contain a number of hazardous substances including plastic that present public health risk.
Knowing that these health hazards exist, can encourage the public to mobilise and demand public health warnings and industry regulation to protect the public. This article discusses these health hazards in tea (does not include the health hazards of the drinking water that the tea is brewed in) and which tea bags are free of endocrine disrupting plastic.
Plastic tea bags were reported not to biodegrade. Worryingly, these teabags have been contaminating composts and food wastes with microplastic globally for decades. In 2017 a gardener in Wrexham UK called Mike Armitage found that tea bags left a plastic residue after being composted. Mike started a petition urging Unilever to remove plastic from bag production. (3) According to the Beverage Standards Association in the UK, 165 million cups of tea are drunk every day and 62 billion cups a year in the UK. On average each person in the UK drinks 3½ cups of tea a day, or 130,000 tonnes in a year, 96% of which are from tea bags. (4) As tea being the most consumed drink in the UK after water, the health risk to humans posed by the plastic pollution and our environment needs urgent consideration.
Plastic in tea
A recent study indicated that steeping a single plastic teabag at a brewing temperature of (95 °C) releases approximately 11.6 billion microplastics and 3.1 billion nanoplastics into a single cup of tea. The composition of the released particles is matched to the original teabags (nylon and polyethylene terephthalate (PETE/PET). A toxicity assessment performed by the researchers showed that exposure to the plastic particles released from the teabags caused dose-dependent detrimental behavioural and developmental health effects. (5)
Despite its name, PET is not a plasticiser phthalate. Phthalates are low molecular weight monoesters. PET is high molecular weight polyester. (6) Studies on PET bottles (recycling code 1) show that phthalates can leach from PET bottles into their contents and that these are endocrine disrupting. (7) The migration of phthalates from packaging depends on the type of liquid, storage time, temperature and bottle type. Another study investigating extent of antimony migration from PET found that antimony leaches from PET plastic drinking water bottles. (8) Antimony in PET is an endocrine disrupting chemical.
Heath implications of microplastics according to the WHO
Very recently it was widely reported that the World Health Organisation (WHO) report found no evidence of a current danger from microplastics. (9) This is not fact. Firstly the report is about micoplastics in drinking water only. Microplastics are ubiquitous. For example, in Germany, plastic fibres and fragments were found in all 24 beer brands tested, as well as honey and sugar. (10). Microplastics in our oceans evaporate into the sky and in our atmosphere providing a source of both outdoor and indoor air pollution. A recent study investigating the atmospheric fallout of microplastics estimated between 3 and 10 tons of plastic fibres are fall on Paris per year (11). The WHO report in fact identified knowledge gaps and made recommendations in respect to monitoring and management of microplastics and plastics in the environment, and to better assess human health risks and inform appropriate management actions. (12)
The WHO profit from plastic
Whilst it is widely accepted that reproductive and developmental abnormalities linked to endocrine disrupting chemical (EDC) exposures have now been documented in birds, frogs, seals, polar bears, marine mollusks, and dozens of other wildlife species, public health appears very reluctant to highlight health risks associated with pollutants that they are in part responsible for in the population. In considering information provided by the WHO in assessing bias, it is important to know that in a bid to make a step-change towards universal health coverage (UHC) the WHO have moved towards a predominant reliance on public funding for the health system including taking income from natural resource revenues including state-owned oil and gas companies in many mineral-rich countries. (13) As the world aims to move from fossil fuels, fossil fuel giants ExxonMobil and Shell, as well as plastic makers like SABIC and Formosa Plastics, are building and massively expanding to turn ethane, a byproduct of natural gas fracking, into polyethylene pellets, which can be made into a variety of plastic products thus inhibiting plastic recycling by sheer overwhelming. (14, 15)
The WHO review on microplastics in drinking water was launched to;
• Review the very scarce evidence
• Identify evidence gaps
• Establish research agenda
• Inform a more thorough risk assessment
Endocrine disrupting chemicals and human health
Endocrine disrupting chemicals (EDCs) include organochlorine pesticides, polychlorinated biphenyls (PCBs), bisphenol A (BPA), phthalates, dioxins and furans (16).
Close to 800 chemicals EDCs, capable of interfering with hormone;
Three strands of evidence give strength to concerns over EDCs:
1. High incidence and increasing rates of endocrine-related disease in humans.
2. Observations of endocrine-related consequences in wildlife populations.
3. Laboratory studies linking EDCs and human health outcomes (17).
EDC diseases & disorders
Female & male infertility: BPA can interfere with hypothalamic-pituitary axis (HPA), such as increasing hypothalamic gonadotropin-releasing hormone (GnRH) secretion and promoting pituitary proliferation (18).
Low sperm count: In up to 40% of young men.
Genital malformations: Cryptorchidisms (non-descending testes) and hypospadias (penile malformations) in baby boys.
Sharp increase in children born with intersex variation IV: Ambiguous genitalia, hermaphrodite, pseudohermaphroditism etc.
Sharp increase in gender dysphoria, transgender & gender neutral: Lesbian, Gay, Bisexual, Transgender, Queer or Questioning and Intersex (LGBTQI) existed pre-industrial revolution.
Precocious puberty: In young girls (risk factor for breast cancer).
Adverse pregnancy outcomes: Preterm birth/low birth weight.
• Cognitive, motor and sensory deficits.
• Neurological impairments (NIs) including neuropathies.
• Neurodevelopmental disorders (NDDs) autism and attention deficit hyperactivity disorder (ADHD).
• Neurodegenerative diseases (NDGs) including Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis (ALS).
• Exposure associated with persistent organic pollutants (POPs), plastic exudates BPA & phthalate (19).
Hormone dependent tumours: Breast, endometrial, ovarian, prostate, testicular and thyroid.
• Polycystic Ovary Syndrome (PCOS).
• Metabolic syndrome: Evidence shows EDCs may contribute to the obesity pandemic evolution and metabolic disorders including Type 2 Diabetes (T2D) (20).
Atopic disorders: Phthalates and BPA exposure are associated with allergies, asthma and atopic dermatitis (21).
Lowered vaccine response
PCBs are POPs meaning they are resistant to environmental degradation and accumulate in the fatty tissue of animals. (22) Plastic fragments, contain organic contaminants, including PCBs. (23) A study of two birth cohorts in the Faroe Islands, where diets may include whale blubber contaminated with PCBs, suggests exposure to PCBs may reduce immune response to childhood vaccinations. (24) Another study in Dutch preschool children measured humoral immunity by antibody levels for mumps, measles, and rubella after vaccination and found that prenatal PCB exposure measured as a higher dioxin toxic equivalent (TEQ) was associated with an increased number of lymphocytes, T-cells, and cluster of differentiation cells, T-cell receptor and T cells and lowers antibody levels to mumps and measles at preschool age. (25)
Plastic free or non-endocrine disrupting bioplastic tea bags
Drinking loose leaf tea using a tea infuser or tea pot is the best choice for the environment.
PG Tips pyramid bags
For those who are looking for a plastic free tea bag, in 2018 PG tips announced a move to using a fully biodegradable, plant based material in its tea bags. The new tea bags have been made using a renewable, plant-based material. Unlike polypropylene the new material is made from corn starch and is 100% biodegradable. All tea bags manufactured by the end of 2018 were to use the new material. This is the first eco-friendly pyramid teabags. (26) Prior to this move plant-based alternatives were already been used in PG Tips ranges throughout Canada, Poland and Indonesia.
PG Tips standard tea bags are not plastic free. PG Tips announced in February 2018 that it was planning to switch to fully biodegradable, plant-based teabags
The Co-op became the first retailer to remove all polypropylene plastic to develop a fully-biodegradable paper tea bag in an attempt to combat plastic pollution. (27)
Clipper declares its bags are “plastic free". Clipper use bioplastic made from non endocrine disrupting polylactic acid (PLA). PLA is a polymer made from renewable resources. Contrary to other thermoplastics which are petroleum-based, some of the raw materials used for PLA's production include corn starch, tapioca roots, or sugarcane. This is a single use biodegradable plastic but not endocrine disrupting and does not pose a threat to human health after degrading. (28)
Pukka tea uses a stitch of cotton instead of heat-sealing its bags. (29)
Abel & Cole
Abel & Cole use Soilon a trademark cornstarch. Abel & Cole removed a page from its website about its "plastic-free tea bags" as the information was not accurate. Bioplastic, whilst plastic, is biodegradable and non endocrine disrupting thus does not pose a threat to human health. (29)
Teapigs says on its website that it’s "tea temples have never contained plastic", Teapigs confirmed their tea bags contain PLA from corn starch. (30)
Tetley standard tea bags are not plastic free. Tetley says its teabags contain a small amount of plastic material (0.04g per bag) so that they can be heat-sealed. It anticipates beginning to introduce fully biodegradable teabags for its core ranges in 2020. (29)
Yorkshire Tea standard tea bags are not plastic free.
Yorkshire Tea announced in October 2019 that it was hoping to release new renewable and biodegradable teabags by the end of November. Like Clipper, Yorkshire Tea will also use PLA. (31) Yorkshire Tea’s new biodegradable teabag however, has been reported to keep splitting and filling cups with sludge. (32)
Twinnings standard tea bags are not plastic free. Twinnings traditional teabag range contains a small amount of oil-based plastic. From January 2020, the range will become plant-based and will biodegrade in industrial composting. Twinnings says some of its "tag" teabags are made from a plant-based paper material that is folded and stitched with cotton thus are plastic free. (33)
PG Tip pyramids bags only
Abel & Cole
Tetley's catering range
Twinings pyramid range
Waitress Duchy range
Teabags with a plastic sealant:
Aldi/Lidl own brand
Taylors of Harrogate
Yorkshire Tea (32)
Other threats in tea (including loose leaf)
Toxic contamination by heavy metals
Large amount of chemicals including heavy metals are applied annually on agricultural soils as fertilisers and pesticides. Such applications result in the increase of heavy metals, particularly cadmium (Cd), lead (Pb), and arsenic (As). (35) The uptake of heavy metals by vegetable plants grown in contaminated cultivation soil is acknowledged. (36) Tea is mainly grown in Asia, Africa, South America and around the Black and Caspian Seas. The four biggest tea-producing countries today are China, India, Sri Lanka and Kenya. (37) It should be noted that tea is also grown in the UK, Australia, Germany, Switzerland and other non classical tea regions. (38) Heavy metal contamination in tea will depend on the quality of the soil in the country in which it is grown. A study found Indian teas for example had the highest percentage of Cd leaching (43.8 %) and Chinese tea has the lowest (9.41 %). Japanese tea had the highest Pb contamination. (39) A toxic contamination study on 30 different black, green, white, and oolong teas sold in tea bags found toxic contamination by heavy metals in most of the teas. Aluminium levels were above recommended guidelines in 20% of brewed teas. As no existing guidelines exists for routine testing or reporting of toxicant levels in "naturally" occurring products, the study recommended that public health warnings or industry regulation might be indicated to protect the public. (40)
Amyotrophic lateral sclerosis (ALS)
Attention deficit hyperactivity disorder (ADHD)
Bisphenol A (BPA)
Endocrine disrupting chemicals (EDCs)
Epigallocatechin gallate (EGCG)
Gonadotropin-releasing hormone (GnRH)
Lesbian, Gay, Bisexual, Transgender, Queer or Questioning and Intersex (LGBTQI)
Neurological impairments (NIs)
Neurodevelopmental disorders (NDDs)
Neurodegenerative diseases (NDGs)
Persistent organic pollutants (POPs)
Polychlorinated biphenyls (PCBs)
Polylactic acid (PLA)
Polyethylene terephthalate (PETE/PET)
Polycystic Ovary Syndrome (PCOS)
Toxic equivalent (TEQ)
Type 2 Diabetes (T2D)
Universal health coverage (UHC)
World Health Organisation (WHO)
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