The numbers behind this shift are remarkable. Africa hosts more than 80 percent of the world’s camel population, and roughly 60 percent of those animals are concentrated in eastern African countries including Sudan, Somalia, Ethiopia, and Kenya. Global camel milk production climbed from around 3 million tonnes in 2017 to 4.11 million tonnes in 2022, with actual output potentially reaching 5.4 million tonnes once underreporting is accounted for. That represents an average annual growth rate of approximately 2.45 percent, a substantial expansion compared with production levels in the 1960s. Projections suggest the global camel population may reach 60 million within the next 25 years, a trajectory driven largely by the species’ unmatched ability to produce milk where cattle and goats cannot.

In Ethiopia, home to an estimated 1.7 to 2.0 million camels concentrated in the Somali, Afar, and Oromia regions, pastoral communities such as the Afar, Somali, Karayu, and Borana rely on camels for milk, meat, transport, and income. Kenya produces approximately 1.165 million litres of camel milk and Somalia about 0.956 million litres, with camel milk accounting for around 40 percent of total milk output in Somalia and 12 percent in Ethiopia. Yet the review’s authors caution that official statistics likely underestimate true camel numbers across the region, because mobile pastoral herds, weak census systems, and cross-border movements confound data collection. Ethiopia serves as a documented example of this undercounting, and similar structural limitations are reported elsewhere in the region.

What makes camel milk scientifically distinctive is its unusual composition. Compared with bovine and caprine milk, camel milk generally contains lower fat, ranging from approximately 2.5 to 4.5 percent, and lower lactose, with protein levels between 2.5 and 3.9 percent. Its most celebrated feature is an exceptionally high vitamin C concentration that far exceeds the negligible levels found in cow and goat milk, a genuine nutritional advantage in regions where fresh fruits and vegetables are scarce. Camel milk is also rich in calcium, phosphorus, potassium, magnesium, and sodium, and contains bioactive components including lactoferrin and immunoglobulins that contribute to a longer shelf life than bovine milk and underpin traditional preservation practices.

At the molecular level, camel milk’s protein architecture sets it apart in ways that are both beneficial and technically troublesome. It lacks β-lactoglobulin, a major cow-milk whey protein associated with allergic reactions in infants, and contains lower levels of κ-casein alongside larger casein micelles and a higher proportion of β-casein. These traits improve digestibility and reduce allergenic potential, with some researchers noting compositional similarities to human milk. But they also create formidable technological challenges: weak rennet coagulation, poor curd formation, extended fermentation times needed to reach target acidity, and instability under ultra-high-temperature treatment. Butter and cheese made from camel milk yield lower outputs and display different textures than their bovine counterparts, which helps explain why the milk has historically been consumed raw or spontaneously fermented rather than processed.

Traditional utilization remains deeply embedded across the region. Pastoral households drink camel milk fresh, ferment it naturally into sour milk products, and use it as the base for camel milk tea, soups, and stews. Fermented camel milk has long been valued not only for its nutrition but for perceived therapeutic properties, and cultural associations with strength, endurance, and suitability for nomadic life generate stable local demand. In recent years, however, technological advances have begun to unlock new product categories: pasteurized milk, milk powder, yoghurt, cheese, ice cream, chocolate, and probiotic beverages have all been produced from camel milk under optimized conditions. Enterprises such as Tiviski in Mauritania, Camelicious in Dubai, and Addis Kidan Milk Processing Enterprises in Ethiopia now supply pasteurized and packaged camel milk to urban consumers and export markets.

The safety picture is considerably less rosy. The review documents marked variability in microbial quality across Ethiopia and neighboring countries, with total bacterial counts in the Somali Regional State of Ethiopia exceeding acceptable limits and indicating contamination along the value chain. Investigations in pastoral areas of Afar and other lowland regions detected Staphylococcus aureus, Escherichia coli, and other indicator organisms in raw camel milk, with contamination levels linked to poor udder hygiene and traditional storage conditions. Pathogens including Staphylococcus, Streptococcus, Listeria, Salmonella, and Pseudomonas species have been isolated from raw samples, frequently originating from the udder in cases of mastitis. The review emphasizes a common misconception: although camel milk’s natural antimicrobial components are real, their effect at ambient temperatures is limited, and inadequate hygiene during milking, collection, and transport readily overwhelms them. Seasonal variation matters too, with bacterial counts typically higher during the wet season.

The value chain connecting pastoralist herders to commercial markets remains largely informal and fragmented. Milk is often transported without cooling or formal quality control, reducing shelf life and increasing microbial risk. In parts of Ethiopia, women sell camel milk along roadsides without hygienic infrastructure or temperature control, and comparable informal systems dominate in Somalia and northern Kenya, where insecurity, poor roads, and insufficient collection centers restrict commercialization. Emerging peri-urban dairies are beginning to bridge the gap by aggregating milk, improving hygiene, and supplying growing urban demand, while informal cross-border trade among Ethiopia, Somalia, and Kenya reflects strong regional interconnectivity. Comparative benchmarks from Kenya, Kazakhstan, Saudi Arabia, and the United Arab Emirates show how investment in mechanization, regulation, and cold-chain infrastructure can transform the sector, though the review presents these as possible pathways rather than direct models.

Structural constraints run deep. The camel sector has historically received limited research investment and policy prioritization, with livestock development programs favoring cattle and small ruminants. Many countries lack national standards for processed camel milk products, and regulatory harmonization among Ethiopia, Somalia, Kenya, Sudan, and Djibouti remains limited, constraining cross-border trade despite robust informal flows. Feed shortages driven by rangeland degradation, deforestation, and recurrent droughts reduce milk output, while inadequate veterinary coverage and recurrent disease outbreaks depress productivity. Dromedaries’ slow reproduction, including a roughly 13-month gestation period and restricted mating season, further limits herd expansion under traditional management. Institutional initiatives such as Ethiopia’s Meat and Milk Institute and the PRIME project have provided training in milk handling and marketing, but sustained interventions remain scarce elsewhere in the region.

Despite these obstacles, the opportunities are substantial. Declining cattle productivity under recurrent drought has pushed pastoralists across northern Kenya, Somalia, and Sudan toward camels, which maintain milk production through prolonged dry periods and thereby stabilize both household food security and raw material supply for processors. Growing health awareness has expanded camel milk’s appeal in urban and niche export markets, and pilot-scale facilities in Kenya and Ethiopia have already introduced pasteurized milk and yoghurt to city consumers. The review’s authors argue that coordinated improvements in processing technology, cold-chain infrastructure, quality assurance, and regional policy harmonization, supported by public-private partnerships and targeted research investment, could transform camel milk from a predominantly informal commodity into a competitive regional and export product. If that transition succeeds, the white gold of the desert may prove to be one of the most consequential climate-adaptation stories in global agriculture, turning one of humanity’s oldest dairy traditions into an engine of food security, employment, and economic resilience for millions of pastoralists across the Horn of Africa.

Subject of Research: Camel milk production systems, nutritional quality, safety, and value chain dynamics in the Horn of Africa

Article Title: Camel milk in the horn of Africa: production systems, physicochemical, and nutritional quality, traditional utilization, safety, and market value chain dynamics

Article References: Mahdi Hassan, S., Bekele Tola, Y., Fikreyesus Forsido, S., Arimi, J., Abera Teka, T., & Makiso Urugo, M. (2026). Camel milk in the horn of Africa: production systems, physicochemical, and nutritional quality, traditional utilization, safety, and market value chain dynamics. Food Science of Animal Resources, 46(1), Article 67. https://doi.org/10.1007/s44463-026-00077-6

Image Credits: AI Generated

DOI: 10.1007/s44463-026-00077-6

Keywords: camel milk, Horn of Africa, pastoralism, dairy production, food security, climate resilience, milk safety, value chain, vitamin C, fermentation, Ethiopia, Kenya

The chemicals in question come from the vast world of technical rubber—tires, hoses, seals, gaskets, and tubing. Every year, an estimated six million tons of tire and road wear particles are released into the environment worldwide as tires grind against pavement. These particles carry a cocktail of additives: vulcanization accelerators that make rubber cure properly, antioxidants and antiozonants that protect it from heat, oxygen, and cracking, and plasticizers that keep it flexible. As tires degrade on the road, these compounds spread through atmospheric deposition, road runoff, and even biosolid fertilizers applied to farmland, embedding themselves in the soils where food is grown and where livestock graze.

Some of these compounds have already earned a troubling reputation. The tire antioxidant 6-PPD and its oxidation product 6-PPDQ became infamous after scientists discovered that 6-PPDQ washes off roads and kills coho salmon in urban streams within hours of exposure. Subsequent work in mice showed that oral exposure to both chemicals caused dose-dependent accumulation in the liver, elevated liver weight, increased triglycerides, and disruptions in glycolipid metabolism, immune signaling, and glutathione pathways. Another rubber additive, the vulcanization accelerator 1,3-diphenylguanidine, or DPG—produced or imported into the European Economic Area at rates of 10,000 to 100,000 tons per year—has been linked in animal studies to reproductive abnormalities, including altered sperm morphology and reduced fertility, and more recently to genotoxic effects in laboratory bioassays.

Until now, however, almost nothing was known about whether these compounds reach milk. Earlier research had shown that tire-derived chemicals such as benzothiazoles, 6-PPD, and 6-PPDQ can be taken up and metabolized by edible plants like lettuce and carrots, with a compound’s lipophilicity strongly influencing how readily it moves through plant tissues. A recent cross-country survey also found p-phenylenediamines and their quinone derivatives in chicken eggs from thirteen countries across four continents, at concentrations reaching thousands of nanograms per kilogram of egg yolk. Milk, consumed in enormous quantities worldwide and produced on farms that often sit beside busy roads and rely heavily on rubber equipment, represented an obvious but unexamined gap in the picture of dietary exposure.

To close that gap, a team led by Florian Breider and Beat J. Brüschweiler collected seventeen raw cow milk samples from sixteen Swiss farms spanning a range of environments: three alpine farms far from major traffic, three farms near highways carrying roughly 50,000 to 150,000 vehicles per day, four farms near departmental roads with 3,000 to 30,000 vehicles daily, and six farms near country roads with only 500 to 5,000 vehicles. Samples were drawn directly from the milk tanks connected to the milking machines and analyzed using liquid chromatography coupled with tandem mass spectrometry, a sensitive technique capable of detecting trace organic compounds in complex matrices. Deuterated internal standards, matrix-matched calibration, procedural blanks, and recovery corrections were applied throughout, though the authors note that the complexity of milk makes the reported concentrations best regarded as semi-quantitative.

The results revealed that seven of the seventeen samples—41 percent—contained at least one rubber-related compound above the limit of quantification. Four compounds were detected: the benzothiazole vulcanization accelerator S-BTH, the guanidine accelerator DPG, the antioxidant 6-PPD, and its oxidation product 6-PPDQ. DPG appeared in 23 percent of samples at concentrations ranging from 38.8 to 223.3 nanograms per liter, with a median of 68.0. 6-PPD was found in two samples at 71.4 to 99.1 nanograms per liter, and 6-PPDQ appeared once at 75.6 nanograms per liter. S-BTH showed up in a single sample at a striking 26,258.5 nanograms per liter—an apparent outlier that the researchers suggest could reflect localized contamination or release from a specific rubber component, though more sampling would be needed to say for certain.

Intriguingly, none of the target compounds were detected in milk from the three alpine farms located away from major road traffic, while detections occurred at farms near country, departmental, and highway roads. That pattern is compatible with reduced environmental exposure to road-related emissions at high-altitude sites, but the study found no clear relationship between traffic intensity and either detection frequency or concentration—several positive samples in fact came from farms along the quietest roads. With a limited number of farms in each traffic category, and with differences in feeding practices, husbandry conditions, and milking equipment potentially confounding the comparison, the authors are careful not to attribute the contamination solely to road traffic. Determining the true contribution of traffic emissions will require larger studies that also measure these chemicals in air, soil, and feed.

That caution is reinforced by the study’s second, perhaps more surprising, finding. When the researchers analyzed eight rubber components taken directly from dairy production systems—teatcup liners, elbow connectors, rubber sleeves, tubing, connectors, and plugs, all of which touch milk during milking, transfer, or storage—they found fourteen rubber-related chemicals in nearly every component. Total bulk concentrations ranged from 42.9 micrograms per gram up to 3.7 milligrams per gram, averaging 817 micrograms per gram, levels comparable to those in car tires. S-BTH dominated at 49 to 715 micrograms per gram, while 6-PPD reached up to 2.7 milligrams per gram and its chemical cousin IPPD up to 921 micrograms per gram. DPG, aniline—a degradation product of several accelerators—and the cyclic amines CPU and DCU were also widespread. The chemical fingerprints of these components closely resemble those of automotive rubber, meaning the same additives raising environmental concerns are sitting inside the equipment that handles milk every day.

The researchers also rinsed the interior surfaces of these components with methanol to estimate how much of the additive load could be released on contact. This worst-case solubilization test does not replicate real milking conditions—milk is an aqueous, fatty matrix rather than an organic solvent—but it demonstrated that the compounds are available for leaching, and that what comes off the surface mirrors the composition of the bulk rubber. The authors stress that no formal migration test was performed, so compliance with existing migration limits cannot be assessed either way. Still, the results establish a theoretically plausible second pathway: rubber parts in milking machines and dairy processing equipment could, under the right conditions of temperature, contact time, and fat content, transfer their additives directly into milk.

That possibility lands in a regulatory gray zone. Under German Federal Institute for Risk Assessment recommendations, milking equipment rubber is generally classified as category 3, short-term food contact, with compositional caps of 1.5 percent for 6-PPD, 0.3 percent for DPG, and 1 percent for S-BTH, and a migration ceiling of 0.3 milligrams per liter for 6-PPD into liquids contacted at 40 degrees Celsius for ten minutes. A 2020 French decree likewise sets specific migration limits for DPG and 6-PPD. But no compositional limits or migration criteria currently exist for the other eleven compounds detected in the dairy equipment, including 6-PPDQ, which was found directly in milk samples. The detection of a transformation product that can form as rubber ages or oxidizes in real use highlights how far regulation lags behind the chemistry.

The measured concentrations in milk were low—nanograms per liter, far below any established health threshold—and the authors are careful to frame the work as an initial occurrence study rather than a risk assessment. It does not capture daily or seasonal variability on individual farms, and it cannot disentangle environmental exposure from equipment-derived migration. But the convergence of two plausible contamination routes, the presence of chemicals with documented hepatotoxic, reproductive, and genotoxic effects in animals, and the sheer scale of global milk consumption all argue for urgency. The researchers call for long-term monitoring of air, soil, and feed on dairy farms, migration studies under realistic milking conditions, targeted risk assessments of chronic dietary exposure, and ultimately the development of safer rubber formulations for food-contact applications. For now, the message is less alarm than awareness: the rubber that keeps the modern world moving may also be leaving faint chemical fingerprints in its food supply, and those fingerprints deserve a closer look.

Subject of Research: Contamination of raw cow milk and dairy equipment with tire-derived rubber additives such as 6-PPD, 6-PPDQ, DPG, and benzothiazoles.

Article Title: Rubber-related chemical contamination in milk: Implications for dairy production systems

Article References: Breider, F., Grandjean, D., Andrey, C., Masset, T., & Brüschweiler, B. J. (2026). Rubber-related chemical contamination in milk: Implications for dairy production systems. Food Chemistry: X, 39, Article 104373. https://doi.org/10.1016/j.fochx.2026.104373

Image Credits: AI Generated

DOI: 10.1016/j.fochx.2026.104373

Keywords: tire wear particles, 6-PPD, 6-PPDQ, diphenylguanidine, benzothiazoles, raw milk, dairy production, food contamination, rubber additives, food contact materials, mass spectrometry, dietary exposure