Why is precipitation today more acid than precipitation in the 1800s?

Precipitation today is more acidic than in the 1800s primarily due to increased emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) from industrial activities, vehicle exhaust, and the burning of fossil fuels. These pollutants react with water vapor in the atmosphere, forming sulfuric and nitric acids, which then fall as acid rain. In the 1800s, industrialization was less prevalent, leading to lower levels of these pollutants and consequently less acidic precipitation. The rise in population and urbanization has further exacerbated this issue in recent decades.