Editor’s note: An earlier version of this story misstated in the article’s final paragraph the county Lacamas Lake is in; it has since been corrected.

PORTLAND, Ore. (KOIN) – Health officials say people and pets should avoid swimming in Lacamas Lake after results from water samples Monday showed elevated toxin levels. 

The cyanotoxins are coming from harmful algal blooms in the lake, Clark County officials said. 

Clark County Public Health has been monitoring the blooms since early July and a warning advisory was in place for a few weeks in July, but was lifted after water quality improved. 

The sample Monday showed cyanotoxin levels were once again above the threshold recommended by the Washington Department of Health. 

Officials will place warning signs at public access points at the lake, but said people should avoid swimming or water skiing and should avoid areas of scum when using motorized boats, paddle boards, kayaks or canoes.

People should not drink the water and should not allow their pets to come in contact with the water. 

Anyone who catches fish in the lake should clean them well and discard their organs. 

Cyanotoxins can be harmful to people, especially young children, and deadly for small pets that drink the water. They can also be dangerous if inhaled or if they come in contact with skin. Inhaled bacteria or toxins could cause wheezing, coughing, chest tightness and shortness of breath. Contact to skin could cause a rash, itching, blisters and eye irritations. 

Swallowing cyanotoxins can cause abdominal pain, diarrhea, vomiting, numbness of the lips, tingling in the fingers and toes, and dizziness.

Clark County Public Health will continue to monitor Lacamas Lake and will take weekly water samples while the algal blooms are present. If the toxins levels become low enough, the posted signs will be updated.