There are various charitable organizations to donate money, and in some cases, volunteer to help the communities, environment, and public health in Bangkok. Always do proper research and look in guide books like Lonely Planet and Rough Guide for more ideas if you are interested in donating your money or time to a charity in Thailand. I have listed various resources in the links below:
BK Magazine Article (Top Charities in Thailand)
What's on Sukhumvit (18 Ways to help in Bangkok)
Pratthanadee Foundation (Empowering Women & Girls)
UN Recognized Environmental Charities
The Culture Trip.com (Volunteer in Bangkok)
World Wildlife Fund-Thailand
UNICEF-Thailand
Green Peace
BK Magazine Article (Top Charities in Thailand)
What's on Sukhumvit (18 Ways to help in Bangkok)
Pratthanadee Foundation (Empowering Women & Girls)
UN Recognized Environmental Charities
The Culture Trip.com (Volunteer in Bangkok)
World Wildlife Fund-Thailand
UNICEF-Thailand
Green Peace