Legal Guide

Can I sue in California if paraquat caused my Parkinson’s disease?

Yes, you can sue in California if you developed Parkinson’s disease after being exposed to the popular weed killer paraquat.

California law holds companies liable for damages resulting from injuries caused by products with defective designs and products with inadequate warnings and instructions. California law also holds companies liable for damages resulting from injuries caused by their negligence. Negligence is the failure to be reasonably careful to prevent harm from happening.

Lawsuits are currently being filed in California and all across the nation alleging that paraquat manufacturers knew or should have known paraquat could cause Parkinson’s disease, but failed to warn the public about it or instruct the public on how to protect themselves from it.

The lawsuits allege that paraquat is defective by design since it can cause Parkinson’s disease when used as intended or in a reasonably foreseeable way. The lawsuits also allege that paraquat makers were negligent because they didn’t adequately test the safety of paraquat and they didn’t warn that it could cause Parkinson’s disease even though they knew or should have known it can.

Parkinson’s disease primarily affects our motor control. The motor symptoms of Parkinson’s disease can be the result of the death of dopaminergic neurons in our brain. These neurons produce dopamine, which is critical to our brain’s motor control. These neurons are also susceptible to being killed by oxidative stress.

Scientific studies have suggested that paraquat may cause Parkinson’s disease by inducing oxidative stress in brain cells via a process known as redox cycling. This redox cycling process, which can repeat itself indefinitely in human cells, where oxygen is plentiful, produces molecules known as reactive oxygen species which can cause oxidative stress in the brain, killing dopaminergic neurons.

Hundreds of animal and in vitro studies have found that paraquat can kill dopaminergic neurons via oxidative stress. In fact, scientists actually give animals paraquat to intentionally give the animals the symptoms of Parkinson’s disease so they can study those symptoms.

Numerous epidemiological studies have linked paraquat exposure to Parkinson’s disease in humans. Studies done in 2009, 2011 and 2013 found that those exposed to paraquat saw two to over three times the risk of developing Parkinson’s disease compared to those who weren’t exposed to paraquat.

The redox properties of paraquat have been known since the 1930s. It has been known that paraquat is toxic due to its redox cycling since the 1960s.

Paraquat is banned or being phased out in the European Union and over 30 countries, including China and Brazil. Its possible link with Parkinson’s disease was specifically mentioned when paraquat was banned in the EU.

Lawsuits claim paraquat manufacturers were negligent in failing to warn about paraquat’s links with Parkinson’s disease since reasonably careful companies would warn about a link which numerous studies have found; a link which prompted the EU to ban the weed killer. Lawsuits also allege that paraquat manufacturers knew about these studies but “actively and fraudulently concealed this information” from the public.

The negligence in these lawsuits appears to rise to the level of gross negligence, which is acting negligently while being aware you’re doing so. Lawsuits are currently seeking punitive damages based on gross negligence, arguing paraquat makers knew they were being negligent when they hid the link between paraquat and Parkinson’s disease from the public.

Lawsuits argue that it is reasonably foreseeable that those who mix and load paraquat into sprayer tanks, as well as those nearby them, will be exposed to paraquat due to spills, splashes and leaks. Lawsuits argue it is reasonably foreseeable that those who spray paraquat and those nearby locations where it is sprayed will be exposed to paraquat due to it drifting in the wind, as well as through touching sprayed plants.

Lawsuits argue it is reasonably foreseeable that exposure to paraquat can cause it to enter the body and ultimately the brain, specifically through the olfactory bulb.

Paraquat is typically formulated with surfactants which help it stick to plants and penetrate them better. However, lawsuits claim these surfactants also help it penetrate the human body better.

Some paraquat lawsuits are involving loss of consortium claims, claiming a loss of companionship on behalf of the plaintiff’s spouse.

Those who have developed Parkinson’s disease after being exposed to paraquat have two years from the date of being aware paraquat caused their disease to file a lawsuit in California.


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