Mercury Rising (and then falling)
https://pubmed.ncbi.nlm.nih.gov/31566127/
Along this path Dorothy, be careful what falls from the sky, and your scarecrow friend might be smart to hold off on his new brain until later.
When mercury (Hg) emission limits are exceeded in a solid waste incinerator, the consequences can be particularly concerning for both human health and the environment. Here are some of the risks associated with excess mercury emissions:
Human Health Risks:
Neurological Effects: Mercury is a neurotoxin. Its most profound impacts are on the nervous system. Methylmercury exposure in the womb, which can result from a mother’s diet or exposure to mercury vapor, can adversely affect a baby’s growing brain and nervous system. Impacts on cognitive thinking, memory, attention, language, and fine motor and visual spatial skills have been seen in children exposed to methylmercury in the womb.
Cardiovascular Effects: Some studies have also suggested a link between mercury exposure and increased risks of cardiovascular diseases.
Immune System: Mercury exposure might weaken the immune system, making individuals more susceptible to diseases.
Digestive and Immune Systems Effects: High levels of mercury exposure can harm the digestive, nervous, and immune systems, lungs, kidneys, skin, and eyes.
Environmental Risks:
Bioaccumulation in Aquatic Ecosystems: Mercury can be converted to methylmercury (its most toxic form) in water bodies. Methylmercury can bioaccumulate in fish and other aquatic organisms. As larger animals consume smaller ones, the concentration of mercury increases up the food chain. Top predators, including some species of fish that humans consume, can have mercury concentrations millions of times higher than the surrounding habitat.
Wildlife Poisoning: Birds and mammals that eat fish can also consume large amounts of mercury, leading to behavioral changes, decreased reproduction, and even death in some species.
Soil and Vegetation Contamination: Mercury deposition can affect terrestrial environments, leading to contamination of soil and vegetation, which can then enter the food web.
Operational Risks for the Incinerator:
Regulatory Penalties: Exceeding mercury emission limits can lead to legal repercussions, financial penalties, and requirements for corrective action by the facility.
Public Perception: Public awareness of the dangers of mercury is relatively high, so violations can lead to significant public outcry, damaged reputation, and possible litigation.
Global Transport: Mercury emissions don’t just stay local. Mercury can undergo long-range transport in the atmosphere, meaning emissions from one location can impact regions far away, making it a global concern.
Given the severe health and environmental risks associated with mercury, many countries have strict regulations governing its emission from industrial sources, including solid waste incinerators. Efforts to reduce mercury emissions include the use of cleaner technologies, air pollution control devices, and international agreements like the Minamata Convention on Mercury.
Dark Matters a Lot 
