The 20 Dirtiest Cities in the U.S.

California has 7 of the 20 cities with the poorest air quality, according to a list complied by Forbes. Bakersfield, which has 60 days of unhealthy air a year, takes the top spot for its hot and dusty weather and proximity to oil fields.

1 minute read

November 17, 2011, 10:00 AM PST

By Kristopher Fortin


On the state level, California regulations on carbon emissions such as a cap-and-trade programs, and reducing vehicle emissions should help improve the air quality in its cities.

Further improvements will be made at the federal level as well. The Environmental Protection Agency's expected rules on power plants will lead to companies either retrofitting plants with new technology, or closing power plants altogether, reports Christopher Helman.

Data from The American Lung Association's State of the Air 2011 report was used to compile this list.

Friday, November 4, 2011 in Forbes

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Get top-rated, practical training

For Lease painted on window of vacant commercial space.

2024: The Year in Zoning

Cities and states are leaning on zoning reform to help stem the housing crisis and create more affordable, livable neighborhoods.

January 8, 2025 - Diana Ionescu

Cyclist on bike in green painted bike lane at intersection with three-story buildings in background.

NACTO Releases Updated Urban Bikeway Guide

The third edition of the nationally recognized road design guide includes detailed design advice for roads that prioritize safety and accessibility for all users.

January 8, 2025 - National Association of City Transportation Officials (NACTO)

Colorado flags draped between buildings in downtown Denver, Colorado.

Denver Pauses Multifamily Development in Westside Neighborhoods Amidst Gentrification Concerns

City officials say the pause on permits for redevelopment projects aims to stop the displacement of long-term residents.

January 9, 2025 - Governing

24-hour parking sign above parking garage entrance through which you can see a white SUV driving

Comprehensive Parking Supply, Cost, and Price Analysis

Every time somebody purchases a vehicle they expect governments and businesses to provide parking for their use. These facilities are costly. For every dollar motorists spend on their vehicles somebody spends about a dollar on parking.

January 16 - Comprehensive Parking Supply, Cost and Price Analysis

Red and white "Wildfire Evacuation Route" sign on signpost.

Learning From Wildfire Evacuations

Researchers are working to understand how people behave during wildfire events and how to most effectively get people to safety during deadly fires.

January 16 - Wired

Empty large outdoor parking lot with green trees in background.

Parking Reform Yields New Housing

As more cities eliminate or reduce their minimum parking requirements, the impact on housing supply is coming into focus.

January 16 - The New York Times

Urban Design for Planners 1: Software Tools

This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.

Planning for Universal Design

Learn the tools for implementing Universal Design in planning regulations.