Experts have warned that handmade plastic toys such as dolls and LEGO pose a danger to children's health. A study found that the majority contain dangerous levels of toxic chemicals that can hinder children's growth and are associated with cancer and infertility. Researchers in Sweden examined levels of two harmful toxins in over 150 old and new toys. Some old toys contain up to 400 times the legal limits of "persistent chemicals," which can take years to break down in the body. The researchers stated that the broader societal trend away from single-use goods is "not always a good thing automatically." Experts at the University of Gothenburg tested 157 different toys, including balls, dolls, figurines, and decorative items. Phthalates have been linked to increased risks of asthma, breast cancer, obesity, diabetes, low IQ, and growth and fertility issues. It is believed that once these durable chemicals enter the body, they interfere with our internal systems and disrupt our DNA, potentially leading to cancer. European Union and UK laws mean that manufacturers cannot use phthalates in concentrations exceeding 0.1% of the total weight of the toy. However, the study found that 30% of new toys contained levels that exceeded those targets. The situation was far worse for old toys, with 84% containing illegal levels of chemicals. The study suggests that reusing and recycling are not always automatically good. Legal restrictions on hidden chemicals in plastic toys have only been established recently, meaning they do not apply to older products.