But, what does this hazardous air quality actually mean for people's health?

For most people, smoke causes mild symptoms like sore eyes, runny nose and an irritated throat.

However, people with conditions like asthma, emphysema and angina are at greater risk because the smoke can trigger their symptoms.

Thick smoke blanketed Leeton shire on Sunday before clearing significantly on Monday, but has returned with gusto again on Tuesday morning.

Respiratory clinical nurse consultant Robyn Paton, from the Murrumbidgee Local Health District, said breathing in smoke can be detrimental to healthy lungs as well as those with existing health conditions.

"There's a certain level of smoke or in fact any pollution that is thought to be reasonable within an environment and when it says it's hazardous, it means that we've gone way beyond that acceptable level," Ms Paton said.

"As far as the smoke is concerned, it will depend on what is burning in the fire as to what chemicals make up the smoke ... there's often ash particles and there can be burnt embers.

"What we're breathing in [here] is lots of particulates which can have detrimental effects even on healthy lungs, but particularly those that already sensitive to asthma or to Chronic Obstructive Pulmonary Disease or any other lung disease."

Ms Paton said when the air quality is poor, the respiratory system has to work harder to be able to get the required amount of oxygen.

"Everyone ... [should] try to minimise the amount of exposure to any form of smoke," she said.

"Shut the doors and windows and turn on the refrigerated air-conditioning to recycle, rather than bringing the air from outside and try to minimise the amount of physical exercise outside.

"If you already know you get asthma or COPD, follow your action plan and take the medications as required that are documented on your action plan."

People with evaporative air-conditioners are advised to ensure the water is being circulated over the batts, which help filter the air.

Ms Paton said certain face masks can reduce ...., but they can be hard to find and don't last for a long period of time.

"If you are going from A to B, then you can do things like tie a silk scarf around your nose, so that you're breathing through that," she said.

"Try to breathe through your nose rather than your mouth ... the nose is a better natural filter for air, so if you can breathe through the nose you're better off."

MORE NEWS

Charles Sturt University's Dr Bruce Graham, adjunct lecturer in the School of Biomedical Sciences, said in the short-term the human body has effective mechanisms to trap most particles before they get to the lung tissue.

"It's quite a complex process," he said.

"Some individuals will react more than others; depending on their physiological makeup and so for some, it's certainly hazardous.

"Smoke in the area at the moment is lower, but it looks like it will re-flare and could see similar exposure as for last weekend."

Dr Graham said, like people with asthma or existing respiratory conditions, older people are generally more vulnerable to poor air quality than younger people.

****

While you're with us, you can now receive updates straight to your inbox every Friday at 6am from The Irrigator. To make sure you're up to date with all news in Leeton sign up here.