By Santiago Limachi and Daniel Ramos

SANTA CRUZ, Bolivia/LA PAZ, (Reuters) – In the lowland Bolivian region of Santa Cruz, facing its worst wildfires on record, nurse Raúl Gutiérrez noted that the acrid smoke's sting is constant, casting an eerie twilight over the day.

The South American nation is on track for a potential record year of wildfires, driven by drought and land clearances linked to burgeoning cattle and grain production, particularly around the affluent farming city of Santa Cruz.

Although the fires have raged for weeks, smoke levels in cities like Santa Cruz and Cochabamba have intensified in recent days, obscuring city monuments in smog. Wednesday's air pollution reading was one of the worst globally.

"The smoke is persistent and strong. We hope it dissipates, but there are no signs of rain," Gutiérrez stated, noting the worst conditions at dawn, dusk, and midnight.

He also mentioned increased respiratory issues, eye problems, and headaches among the populace, leading to suspended school classes.

"The sun has an orange hue, resembling the moon at night," he remarked.

Inhaling wildfire smoke can be fatal or result in long-term breathing issues; a June study in the journal Science Advances revealed it caused at least 52,000 premature deaths in California over a decade.

Satellite images indicate alarming levels of particulate matter and carbon monoxide in the air. Data from Brazil's INPE shows Bolivia might face its highest number of active fires on record in September.

'THE AMAZON IS BURNING'

Diego Rojas, head of the Department of Water and Atmospheric Pollution at Santa Cruz City Hall, urged residents to avoid outdoor activities and wear masks against the smog.

"We've had five consecutive days with dangerous pollution levels," he said.

These fires have forced school closures and suspended some commercial flights. President Luis Arce has sought international assistance and asserted that the government will persist until the fires are extinguished.

Wilber Melgar, from an Indigenous community in Beni, north of Santa Cruz, attributed the fires to ranchers clearing extensive land for grazing, often using slash-and-burn techniques.

"Right now the Amazon is burning," he expressed.

Brazil is also grappling with a fierce start to its fire season, with major cities enveloped in smoke and large areas of the Amazon rainforest ablaze. The entire region faces its worst fires since 2010.

In Bolivia, Santa Cruz has experienced about 8 million hectares (19.8 million acres) of deforestation in the past 20 years, according to researcher Alcides Vadillo from the Tierra Foundation, leading to more fires.

"Last year, Santa Cruz was the most polluted city globally for a week. This year, it could happen again, posing direct health risks," Vadillo stated.