Microplastics have been detected in breast milk and in meconium, the first stool of the child.

In experimental studies conducted to explain the effects of microplastics on the immune system; especially exposure during early developmental stages has been reported with the following findings:

* The presence of neurotoxicity has been reported; they are related to the activation of immune cells and oxidative stress in the brain.

* They cause disruptions in synaptic excitation/inhibition balance ratios

* They cause neuronal damage in the cerebral cortex and hippocampus.

* They cause anxiety-like behaviors; leading to changes in the ratio of excitatory neurotransmitter proteins,

* They cause an increase in acetylcholinesterase enzyme activity and a decrease in acetylcholine efficacy.

* They cause an increase in serum levels of threonine, aspartate, and taurine and a decrease in phenylalanine levels.

In humans, exposure to microplastics in infants;

*  They cause an increase in oxidative stress which leads to disruptions in ATP synthesis in mitochondria, resulting in impairments in the functions and behaviors of children with autism.