✅ Yes, the content seems to be true and authentic, as reported by several sources.

These, include:

1. https://www.civilsdaily.com/news/pib-indian-researchers-introduce-toxicity-standard-of-pm2-5-pollution/ - (Trust Score 7/10)

- A new toxicity standard for PM2.5 in Kolkata sets the critical threshold at 70 µg/m³, below which toxicity remains stable, but it sharply increases once the concentration exceeds 70 µg/m³.

2. https://pib.gov.in/PressReleaseIframePage.aspx?PRID=2120919 - (Trust Score 8/10)

- A study conducted in Kolkata shows that the toxicity value of PM2.5 experiences a sudden jump when the pollution reaches around 70 µg/m³. The study emphasizes reducing pollution sources, particularly biomass and solid waste burning, which contribute significantly to high PM2.5 levels and increased toxicity in Kolkata.

3. https://www.newkerala.com/news/o/indian-researchers-introduce-toxicity-standard-pm25-pollution-665 - (Trust Score 6/10)

- Indian researchers from the Bose Institute have discovered a critical threshold in PM2.5 pollution that dramatically increases its toxicity. The study found that up to a threshold of around 70 µg/m³, the toxicity remains relatively stable, but beyond this point, the toxicity experiences a sudden and sharp increase.

4. https://www.mid-day.com/lifestyle/nature-and-wildlife/article/indian-researchers-introduce-toxicity-standard-of-pm2-5-pollution-23517693 - (Trust Score 7/10)

- The study, led by Prof. Abhijit Chatterjee, focused on the toxicity of atmospheric aerosols over the atmosphere of Kolkata. The researchers explored how the degree of toxicity changes with the increase in total aerosol pollution load and have studied the oxidative potential of ultrafine aerosols (PM2.5).

5. https://www.devdiscourse.com/article/science-environment/3343366-new-study-toxicity-of-pm25-in-kolkata-shows-sudden-surge-beyond-70-gm3 - (Trust Score 6/10)

- The study demonstrated a non-linear relationship between PM2.5 concentration and its oxidative toxicity. Up to a threshold of around 70 µg/m³, the OP or toxicity of PM2.5 remains relatively stable, but beyond this point, the toxicity experiences a sudden and sharp increase, peaking near 130 µg/m³.