Capitalist profit driven economy invented electricity, factories, machines, cars, planes, plastic, countless chemicals, massive use of coal and many other things harmful for environment. Overwhelming majority of things harmful for environment were invented or massively used after year 1700 by the very same profit driven economy which you label as Capitalism.
The only countries on Earth which are somewhat less polluted are those in which government regulated and limited economy. All the major sources of pollution are private companies and private individuals, same is true for China which is also a profit driven economy.
Since free market is the most profit driven economy there is, and profit driven economy leads to pollution of the environment, then capitalism pollutes the environment much more than systems which are designed to save environment, and systems designed to save environment cannot be Capitalist systems, cannot be profit driven systems.
To make it simple, profit driven systems are based on increasing output, which produces great amount of trash, waste and pollution.
Again, the trash and chemicals and waste which are the main source of pollution didnt even exist until somewhat 300 years ago, when profit driven economy produced and mass used them, as well as mass using other types of pollution.
Plastic production has sharply increased over the last 70 years. In 1950, the world produced just two million tonnes. It now produces over 450 million tonnes. Thats 225 times more.
In 1950 the world emitted 6 billion tonnes of CO2. By 1990 this had almost quadrupled, reaching more than 20 billion tonnes. Emissions have continued to grow rapidly; we now emit over 35 billion tonnes each year. Thats 6 times more, yet population didnt increase by 6 times since 1950. It merely increased by 3 times. So we have 3 times more population, yet 6 times more pollution by CO2.
The results have shown that river pollution occurs mainly due to discharges of wastewater from farms and sewers, and they have also pointed out the contamination of water with mercury and cadmium. They are especially conscious of factories operating in the steel and agricultural industries.
Rivers are polluted by mass producing chemicals which werent even being produced until profit driven economy took greater place, and now we have much greater number of chemicals finding their place in rivers and environments.