Context: Environmental damage in Thuringia has been reduced to a large extent after 1990. The condition of forests, rivers and air was improved by modernizing factories, houses (decline of coal heating) and cars, and contaminated areas such as the former Uranium surface mines around Ronneburg have been remediated. Today's environmental problems are the salination of the Werra river, caused by discharges of K+S salt mines around Unterbreizbach and overfertilisation in agriculture, damaging the soil and small rivers.

Question: Since when has environmental damage in Thuringia been reduced?
Answer: 1990

Question: What is one thing that helped to improve condition of forests, rivers and air?
Answer: modernizing factories

Question: What has been done to former Uranium surface mines around Ronneburg?
Answer: Uranium surface mines around Ronneburg have been remediated

Question: What are today's big environmental problems?
Answer: the salination of the Werra river

Question: What is causing the salination of the Werra river?
Answer: discharges of K+S salt mines around Unterbreizbach

Question: When has environmental damage in Thuringia been increased since?
Answer: Unanswerable

Question: What is one thing that helped to ruin condition of forests, rivers and air?
Answer: Unanswerable

Question: What has never been done to former Uranium surface mines around Ronneburg?
Answer: Unanswerable

Question: What are today's small environmental problems?
Answer: Unanswerable

Question: What is helping improve the salination of the Werra river?
Answer: Unanswerable