Background

Spices are a commonly adulterated food product and studies have demonstrated that the addition of lead chromate pigments has become a practice of some stakeholders in spice supply chains. The addition of lead pigments can increase the vibrancy of a spice’s colour, and thereby make it more appealing to many customers.

Lead has toxic effects on almost all body systems and is especially harmful for children and pregnant women. Lead poisoning can irreversibly damage cognitive development, impact educational attainment, and undermine a child’s potential. Lead poisoning can be symptomless, or it can present with mild symptoms such as headaches, fatigue, stomach discomfort, or nausea, meaning it can easily go undetected.

UNICEF estimated that, in 2019, 644,000 children in Türkiye and 18,028,525 children in Ethiopia were suffering from lead poisoning, measured as a blood lead level greater than 5 μg/dL. There are many sources of lead exposure and the contribution of adulterated spices to the global burden of lead exposure is not yet clear: it is a relatively under-studied source with the potential to contribute a significant burden of disease. To our knowledge, LEEP’s studies represent the first dedicated investigation into the use of lead chromate pigments in the spice industries in Türkiye and in Ethiopia.

The World Health Organisation recommends a lead content limit (variable between food types) of 0.1 – 0.5 ppm. From discussions with subject matter experts on the adulteration of spices with lead pigments, LEEP understands that the expected minimum total lead content in a spice adulterated with a lead pigment is 10 ppm. A measured total lead content below this level is suggestive of incidental environmental contamination at some point in the supply chain.

Türkiye

In 2023, LEEP conducted a study to determine the lead content of spices available for purchase in Türkiye.

30 spices were obtained in February 2023 from six urban centres in Türkiye: Istanbul, Ankara, Artvin, Ardahan, Rize, and Izmir. These urban centres are situated in regions that contribute 59.84% of the national population. Artvin, Ardahan, and Rize were selected because of their proximity to the southwestern region of Georgia, where spice adulteration with lead chromate has previously been identified.

Where available, LEEP purchased spices known to be valued for their colour or that are associated with bright colours. Spices purchased in this study were: turmeric, saffron, flaked red pepper, paprika, chicken seasoning, sausage seasoning, Ottoman spice, curry powder, sumac, cinnamon, and meatball spice. The spices were purchased either loose or pre-packaged.

Number of samples collected in Türkiye by product type. No sample was found to have lead content suggestive of intentional adulteration with lead pigments.

All samples were analysed at Invenura Laboratory (Izmir, Türkiye) using inductively coupled plasma mass spectrometry (ICP-MS). All 30 samples were found to have less than 2 ppm lead content. The range of total lead content was 0.017 – 1.355 ppm. The median total lead content was 0.298 ppm.

Ethiopia

In August 2023, LEEP conducted a study to determine the lead content of spices available for purchase in Ethiopia. The study was conducted in collaboration with PAN-Ethiopia, an NGO based in Addis Ababa.

211 samples were obtained in August 2023 from three urban centres in Ethiopia: Addis Ababa, Adama, and Arba Minch.

Where available, LEEP purchased spices known to be valued for their colour or that are associated with bright colours. Spices purchased in this study were: turmeric, chilli, and pepper. Three of the turmeric samples (1.4% of all samples) were sold as imported from India, and one other turmeric sample was advertised for cosmetic use. Other spices that were purchased include berbere (an Ethiopian spice mixture), and shiro (chickpea flour), both of which are used in richly coloured dishes. The spices were purchased either loose or pre-packaged from formal (e.g., stores built with brick and mortar selling packaged goods) and informal market vendors (i.e. spice market vendors selling loose spices). In addition to the spices, three food colourant samples purchased from markets in Addis Ababa were analysed for lead content. In the case of packaged spices or colourants, the samples were bought on only one occasion.

Number of samples collected in Ethiopia by product type. No sample was found to have lead content suggestive of intentional adulteration with lead pigments.

All samples were packed in polyethylene bags and underwent preliminary analysis with X-Ray spectrometry. LEEP conducted this analysis in the United Kingdom using the SciAps X-550Pb, using a cut-off point of 5 ppm for signs of adulteration with lead pigment. We did not detect lead levels above 5 ppm in any of the 211 samples.

A subset of 31 samples was analysed at Food Forensics Limited (Norwich, United Kingdom) using inductively coupled plasma mass spectrometry (ICP-MS). All 31 samples were found to have less than 2 ppm lead content. The range of total lead content was 0.04 – 0.67 ppm. The median total lead content was 0.15 ppm.

Discussion

The data in both studies suggests that the samples we have analysed were not adulterated with lead pigments. There are some study limitations to consider: 

1. The studies represent only a snapshot of the market taken at a single point in time.
2. The sampling method in both studies was not totally exhaustive. The Türkiye study was limited by a small sample size, but did have good geographical coverage. The Ethiopia study did cover a good proportion of spice producing regions and also included a large number of samples.

Readers may also note that some samples in both studies exceeded WHO’s recommended lead content limit of 0.1-0.5 ppm, which does not indicate adulteration. Whilst it does remain a concern, the focus of our studies was identifying specifically whether there is a practice of adulteration with lead chromates. We expect that any spices adulterated with lead chromate should have a lead content well above 5 ppm – no sample in either study exceeded this threshold.

Accepting some weaknesses, we were still able to analyse the types of spice that are most likely to be adulterated, and to collect them from a variety of geographical areas in each country. Overall, we anticipate from the results that the adulteration of spices with lead pigments is unlikely to be a widespread practice in Türkiye or Ethiopia.

Next steps

The body of evidence that precedes these studies suggests that spices are a commonly adulterated food product. Spices can be adulterated for various reasons, such as enhancing colour or increasing weight. Evidence of hazardous levels of lead have been found in spices sold in Bangladesh, Georgia, and also imported into the United States. The data suggests that lead pigments were added to these spices to enhance colour.

LEEP undertook two studies to identify whether adulteration of spices with lead pigments is a common practice in Türkiye and Ethiopia. The results of the studies provide some encouragement: neither study found high levels of lead that would suggest adulteration with lead pigments.

Lead remains an unnecessary ingredient in spice production and processing. These studies represent LEEP’s first investigations into spices as a source of lead exposure. We are planning similar investigations in other countries as we seek to better understand the burden of global lead exposure that can be attributed to adulterated spices. This understanding will inform our ongoing mission to end childhood lead poisoning.

Acknowledgements and thanks

• Thanks to Berke Çelik, LEEP’s research partner for the Türkiye spice study. Berke conducted and coordinated sample selection, purchasing, sampling, and testing.
• Thanks to PAN-Ethiopia, LEEP’s research partner for the Ethiopia spice study.
• Thanks to Dr Tadesse Amera (Executive Director of PAN-Ethiopia), who hosted LEEP for the duration of the study.