Polychlorinated biphenyls (PCBs) are chemicals with chlorine in their structure. They were once used to make carbonless copy paper, as liquids to transfer heat, and as materials to help electrical equipment work and stay cool. PCBs are very harmful and can cause cancer.
Endocrine disruptors, also called hormonally active agents, endocrine disrupting chemicals, or endocrine disrupting compounds, are chemicals that can interfere with the body’s hormone systems. These chemicals may lead to many health problems, such as changes in sperm quality and fertility, issues with reproductive organs, endometriosis, early puberty, changes in the nervous or immune systems, certain cancers, breathing difficulties, problems with metabolism, diabetes, obesity, heart issues, growth delays, learning challenges, and other problems. These chemicals are found in many household and industrial products.
Surface runoff, also called overland flow or terrestrial runoff, is water that flows over the ground’s surface. This is different from channel runoff, which is water that flows through streams or rivers. Surface runoff happens when rainwater, stormwater, melted snow, or other water sources fall faster than the soil can absorb them.
An algal bloom is a sudden increase in the number of algae in freshwater or ocean water. These blooms can be harmless or harmful. Algal blooms often make water look different in color because of pigments in the algae.
Eutrophication is a process in which nutrients build up in a body of water, leading to the rapid growth of plants and algae. This growth can use up oxygen in the water, making it hard for other living things to survive. This often happens when chemicals used to help crops grow are carried by rain into rivers, lakes, or other water sources.
Water quality means the chemical, physical, and biological traits of water based on how it is used. These traits are often compared to a set of rules to check if the water meets requirements, which is usually done by treating the water. Common rules used to monitor water quality show how healthy ecosystems are, how safe the water is for people, how much pollution is present, and the condition of drinking water.
Water pollution is when water becomes dirty or polluted. This can happen in lakes, rivers, oceans, and other water sources. It is usually caused by human actions.
The Clean Air Act (CAA) is the main federal law in the United States that helps control air pollution across the country. First passed in 1963 and changed many times over the years, it is one of the earliest and most important environmental laws in the United States. Like many major U.S.
An air quality index (AQI) is an estimate of how polluted the air is now or how polluted it is expected to become. When air pollution increases, the AQI also increases, and this means greater risks to public health. Each country has its own air quality index based on its own air quality standards.