A new study published in the journal Environmental Health Perspectives
has confirmed that plastic nanoparticles can cross the human placenta, possibly exposing the developing fetus to a deluge of microscopic toxins and chemicals that are increasingly used in medicines, vaccines and personal care products.
In the study, researchers collected placentas from consenting women immediately after their full-term babies were born. The maternal side of each placenta was injected with a single dose of a solution containing polystyrene nanoparticles. Polystyrene is a widely used plastic that is used to make products such as packing peanuts, disposable coffee cups, #6 plastic food packaging and hard plastic items like disposable cutlery and CD cases.
The researchers used fluorescent polystyrene nanoparticles so that their migration could be tracked. They tested four different sizes with diameters of 50, 80, 240 or 500 nanometers and used at least four placentas for each nanoparticle size. They found that the smaller nanoparticles (50, 80, and 240 nanometers) appeared on the fetal side of the placenta within 15 minutes after injection, while the larger particles (500 nm) stayed on the maternal side for the six-hour duration of the study.
Nanomaterials are itty-bitty particles, often smaller than the diameter of a hair, that have become quite popular in medicine and personal care products where their small size helps move drugs and ingredients through the body. Their smaller size allows them to penetrate more deeply than their larger counterparts. However, they also tend to be more potent and to behave differently in the body than larger molecules.
Take, for example, the nanoparticles used in sunscreen products. In an effort to minimize the “white nose” effect, some mineral sunscreen manufacturers are using formulas containing nanometer-sized particles of their chemical components. This allows the product to be absorbed into the skin more readily (so that it becomes transparent). However, titanium and zinc oxide are two chemicals that you don’t want to absorb into your skin. Unlike larger particles of titanium oxide, nanoparticles of this substance can enter the bloodstream and damage brain cells.
While not much is known about nanoparticle toxicity, animal and laboratory studies have found the very small materials can affect brain cells, DNA and lung function. Animal studies point to reproductive changes, embryo death and brain and nerve damage.