Statement 1 is correct: Gold mining is poisoning Amazon forests with mercury. To separate the gold, miners mix liquid mercury into the sediment, which forms a coating around the gold.

Statement 2 is correct: Fly ash generated by TPPs is one of the ways mercury is released into the environment. Fly ash is usually disposed of in ash ponds in the form of ash slurry, forming an aquatic ecosystem of its own. Coal-based TPPs are the major source of mercury – the ninth most toxic element found on earth — emissions into the environment. Mercury contributed over 80 percent of emissions released by the TPPs, according to 2016 estimates by the Delhi-based think-tank Centre for Science and Environment.

Statement 3 is correct: According to major public health bodies like the World Health Organization (WHO), there is no known safe level of exposure to mercury. Mercury (especially its organic form, methylmercury) is a highly potent neurotoxin. It poses a severe risk to the developing nervous system, making fetuses, infants, and children particularly vulnerable. Regulatory agencies set reference doses or tolerable weekly intakes to guide fish consumption, but these are risk-management thresholds (levels below which adverse effects are unlikely), not a "safe" level.