Karachi has many environmental issues that are a subset of larger issues in Pakistan, severely affecting its biophysical environment as well as human health. The industrialization as well as lax environmental oversight have contributed to the problems. The various forms of pollution have increased as Karachi which has caused widespread environmental and health problems. Air pollution, lack of proper waste management infrastructure and degradation of water bodies are the major environmental issues in Karachi.

Presence of any one of the heavy metal contamination necessitate the need for the estimation of other heavy metals as significant positive correlation was found between chromium and lead concentration, indicating the possibility of similar contamination sources in Karachi.

The Karachi coastline, which stretches over 135 km, is facing severe pollution due to a combination of industrial, port, municipal, and transportation activities in the area. The coastline is being overwhelmed with water-borne pollution being discharged in the shipping process into the marine environment. A recent study found that some of the marine life was contaminated with lead, which if consumed by humans through seafood, has been linked to anemia, kidney failure and brain damage. In fact, the study also discovered that even the mangrove forests protecting the feeder creeks from sea erosion as well as a source of sustenance for fishermen are threatened by this pollution. In the Korangi Industrial Area, 2,500 industrial units including 170 tanneries dispose untreated waste into the Arabian Sea.

Karachi is the largest city in Pakistan and the 12th largest city in the world is facing a significant air pollution problem. The air quality of Karachi has been deteriorating over the years, with pollution levels often exceeding safe limits set by the World Health Organization (WHO).

A 2025 analysis by Climate TRACE of the urban areas with the most people exposed to unhealthy levels of air pollution identified Karachi as the largest.

The Light pollution includes light trespass, over-illumination and astronomical interference. Light pollution is the presence of anthropocentric and artificial light in the night environment. It is exacerbated by excessive, misdirected or obtrusive use of light, but even carefully used light fundamentally alters natural conditions

Noise pollution which encompasses roadway noise, aircraft noise, industrial noise as well as high-intensity sonar. The noise for Karachi came to 80 dB (A), the General Noise Index x (G.N.I.) to 460, and the noise pollution level (N.P.L.) to 99 dB (A). These values are significantly higher (P less than 0.01) than the available international data. The sources of noise production were identified as, the road traffic, human activity, industrial and civil works, mechanical and engineering workshops. The most noticeable sources of noise pollution in Karachi, are the autorickshaws, trail motor bikes and the fag horns of public transport. The noise emanating from a wide variety of sources such as; Motorcycles, Auto-Rikshaws, Cars, Wagons, Mini-buses & Buses, Trucks, Tractors, Water tankers, Bulldozers and Machine drills etc.

Soil contamination occurs when chemicals are released by spill or underground leakage. Among the most significant soil contaminants are hydrocarbons, heavy metals, MTBE, herbicides, pesticides and chlorinated hydrocarbons.