Lead in lipstick may have been on your radar for a while, particularly lead in red lipstick. But lead’s not alone. Other metals may be found in toxic concentrations in your lipstick. Researchers at the University of California Berkeley released a very small study last month showing the results after they tested lipstick for lead (Pb), aluminum (Al), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), magnanese (Mn), nickel (Ni), and titanium (Ti) (Environmental Health Perspectives). One of the reasons that lipsticks get more press than other makeup is the close proximity to the mouth. Guidelines for topical application might be different from those for what can be ingested, but lipstick spans those categories. Cadmium, in particular, has been one that’s been pointed out because it’s a known human carcinogen (Agency for Toxic Substances and Disease Registry).
About the Study
In the study, researchers had teenage girls give them their most favored products to test for the amount of heavy metal impurities in their products. Some level of impurity is expected. As a draft of Canada’s heavy metal impurities guide explains, impurities exist due to the persistent nature of these substances and the fact that they are found in the natural environment (Health Canada). The study researchers used two scales to decide the maximum levels of the metal. Aluminum, copper, cadmium, nickel, and lead were gauged using the levels recommended by the California Environmental Protection Agency (CA EPA) for how much of these heavy metals are allowed in drinking water. Some were gauged using the no observed adverse effects levels (NOAELs) or lowest observed adverse effects levels (LOAELs) as well as uncertainty factors (UFs). Others were compared to the carcinogenic risk, California Reference Exposure Level (REL), and relative intake indices. Cadmium had a NOAEL of 19 µg/day and a UF of 50. The uncertainty factor accounts for the fact that some humans may be extremely sensitive. In this case it was “5 for protecting sensitive individuals, 10 for cancer risk due to oral exposure to cadmium.” Some of the products tested at more than 20% of the estimated acceptable daily intake with average daily use for one product with average use and 10 products considering high usage.
Where Else Do You Get Cadmium?
Cosmetics aren’t the only place where we’re exposed to cadmium; they’re also not the place with the most cadmium exposure. The drinking water guidelines from the CA EPA found that cadmium comes from air, water, food, and smoking. They estimates the daily intake of cadmium from air was 0.01 µg/day, from water was from 0.02 to 2 µg/day, from food was 10 µg/day, and from smoking was from 4 to 6 µg/day. It’s possible to get even more cadmium depending on the area you live in. For example, mining in a particular area in Japan polluted the water used to grow rice, which caused the rice to have high levels of cadmium that affected the population. So, while it’s important to have oversight and vigilance in the ingredients in cosmetics, it’s also important to know where we’re at the biggest risk for excessive cadmium exposure.
Cadmium Exposure Issues
On the one hand, excessive exposure to cadmium has a whole host of negative effects. Unfortunately, studies seem to suggest that women might be more seriously affected than men by exposure to cadmium. In the aforementioned Japanese study, the increase of cadmium in rice resulted in a significant increase in mortality for women, but not for men (Toxicology Letters). And there are a host of issues that come with cadmium exposure in tests on both humans and animals, including renal toxicity in people who worked in a battery manufacturing plant (Acta Medica Scandinavica); respiratory and lung issues in animals (ATSDR); reduced birth weight and maternal toxicity in animals; and carcinogenicity when consumed, injected, and inhaled by animals; as well as kidney and bone issues from oral exposure. It’s important to remember, however, that many of these studies observed people and animals with far higher exposure to cadmium than your lipstick. They were also either directly consuming cadmium or exposed to huge amounts over time. Topically applied cadmium has a low absorption into the skin, because it adheres to epidermal keratin (Applied Organometallic Chemistry). High topical concentrations over several hours or occupational exposure are problematic, however.
This data isn’t necessarily new or shocking, but it further illustrates why some have been calling for a change in legislation that would allow the FDA more oversight in the ingredients in cosmetics. The amount of cadmium in lipsticks can be greater than 20% of the acceptable daily limit, but these lip products didn’t surpass the acceptable daily limit. As Sa Liu, a researcher of environmental health sciences noted, “We don’t want to cause any panic in the users or consumers … We don’t think it will cause any harm in the short term, but the more you use and the longer you use it, the more likely a person may get overexposed (to the metals) and potentially be taking higher risk for adverse effects.” This study shows that it’s important to look at the ingredients in our cosmetics, in the concentrations they exist in, and test the effects on humans. Other countries have taken to implementing more regulations, and the researchers of this study call for the U.S. to do the same.