The number of people in the Netherlands with Parkinson’s disease has gone up 30% over the past decade, according to a new study, published in Dutch medical journal NTG.

The research, carried out at several Dutch hospitals, shows that the increase is due to both pollution and pesticides, and that fact the population is getting older, lead researcher Bas Bloem told the AD.

The amount of “junk in the environment”, including pesticides, is a major factor, Bloem said. “We know that farmers and market gardeners have much more risk of developing Parkison’s and people living close to arable farms also have a higher risk.”

Parkinson’s is widely thought to be a disease that only affects older people but one in three patients is under the age of 65 and that includes people in their 20s and 30s, he said. The youngest patient so far is 13.

Ten years ago, 40,000 people in the Netherlands had been diagnosed with Parkinson’s or symptoms that resemble the disease. That figure has now risen to 63,500.

Parkinson’s is a brain disorder that causes unintended or uncontrollable movements, such as shaking, stiffness, and difficulty with balance and coordination. Symptoms usually begin gradually and worsen over time and there is currently no cure.

In June a court in Assen has ruled that a lily bulb grower must stop using pesticides because they may be causing neurological diseases, but the case was later overturned on appeal.

The lower court judge said the claimants had a legitimate concern that their exposure to a mix of pesticides put them at risk of contracting diseases such as Parkinson’s disease, the muscle wasting disease ALS, and Alzheimer’s disease.

Last year, European research led by Wageningen University showed that 42% of Dutch farmland has excessive levels of nitrogen and phosphates, in addition to widespread contamination with pesticide compounds.