Dozens of weekend sporting fixtures and outdoor activities are likely to be affected by unprecedented poor air quality caused by drought and bushfire smoke.
Lower Hunter air quality has at times rivalled that of the most polluted parts of the world during the past week. The Lower Hunter air quality index hit 647 at 4pm on Wednesday - the safe range is under 100.
Hunter New England Health Emergency departments have also had a 30 per cent increase in presentations for respiratory conditions, such as asthma, compared to the same time last year.
"It is certainly the worst we have seen since the installation of the Lower Hunter air quality monitoring network," public health physician David Durrheim said.
"What is particularly concerning is the is amount of fine particle pollution (PM2.5) which can get into the lungs."
Poor air quality has already already resulted in the cancellation of a little athletics meeting in Newcastle on Monday night and an under 16s junior cricket match at Speers Point on Wednesday night.
"We are monitoring the situation very closely and we won't make a final decision until Saturday morning," Newcastle Junior Cricket Association president Andrew Standing said.
Mr Standing said it was difficult to make a blanket decision due to the age range of the association's players (under 10 to under 18) and fact that games were played between Port Stephens and Swansea.
"You could have a situation where there air is clear in Toronto but hazardous in Nelson Bay. The last thing we want is someone getting sick from playing cricket," he said.
Newcastle District Cricket Association chairman Paul Marjoribanks said the issue was yet to be raised with the association.
Director of Sunday morning's Variety Santa Fun Run Paul Humphreys said he was hopeful a forecast wind shift late on Saturday would create favourable conditions for the thousands of participants who traditionally participate in the event.
"It's certainly a consideration for us," he said.
"We are hopeful that it will clear up but if it was hazardous we would probably have to cancel it," he said.
People with preexisting respiratory conditions are advised to limit time spent outdoors.
Anyone who experiences difficulty breathing, chest tightness or increased wheezing should seek medical help.
For more information visit: NSW Health
