atmosphere

biohazard

catastrophe

contamination

dirty

disposal

dump

dumping

earth

eco

ecologist

ecology

environment

garbage

glass

global

hand

harmful

hazard

human

impact

junk

landfill

level

liquid

littering

magnifying

mess

nature

planet

plastic

pollution

problem

puddle

recycle

recycling

research

researcher

responsibility

reuse

rubbish

save

scientist

scrap

social

substance

toxic

trash

volunteer

waste