Strawberry Fields Forever? California's Pesticide Addiction Harms Local Communities

If you've eaten strawberries recently, you can probably thank a California grower. Mild temperatures and an extended growing season mean that at least 80 percent of strawberries sold in the U.S. originate from the state. However, new research suggests that the tasty fruit comes with a heavy price for local communities because of the extensive use of harmful pesticides. Those living near strawberry fields face higher risks of cancer and other health problems from exposure to the chemicals.

Last month, the Center for Investigative Reporting released an interactive map showing where pesticides are used in California. This important tool helps communities understand the chemicals used in their area and learn about their health risks. The map is part of a larger investigative project into the dangers associated with California's strawberry farming. 

Mapping California's Toxic Hotspots

The map divides California into townships and shades them by the amount of pesticides used on crops between 2003 and 2012. (Townships are usually one square mile apiece and are what the state uses when tracking pesticide applications.) Users can choose to view four different map layers:

  • Chemicals of Concern are pesticides considered particularly harmful to communities, according to the California Department of Public Health. These include cancer-causing chemicals, neurotoxins, and chemicals that disrupt development.

  • 1,3-D Overages shows the townships that exceeded the state's annual limit on 1,3-dichloropropene (1,3-D) between 2003 and 2012. 1,3-D is a gas that is used to kill pests in the soil. Exposure to 1,3-D can increase a person's risk for cancer.

  • All Fumigants include 1,3-D and other pesticides used to sterilize soil prior to planting. Fumigants used in strawberry farming include methyl bromide, an ozone-depleting gas, and chloropicrin, which originated as a chemical weapon in World War I.

  • All chemicals include any pesticides used in agriculture, whether or not they have public health concerns.

The interactive map allows users to zoom into particular regions or search by city or address. Users can then click on individual townships to learn the total volume of pesticides used between 2003 and 2012. The pop-up box also lists the most commonly used chemicals and their health concerns.

It is important to note that the map shows the potential pesticide exposure for communities. Actual exposure depends on a number of factors, including weather patterns and safety measures used during application. Even so, the map reveals some alarming trends surrounding pesticide use in California, which raise important questions about the types of pesticides being used and restrictions on the activities that pose the greatest exposure risks to nearby communities.

Key Findings

Twenty-two million pesticide applications occurred in California between 2003 and 2012. This amounts to 1.5 billion pounds of chemicals. (Note that this only includes agricultural uses; other applications – such as pest extermination in buildings – are excluded from this analysis.)

Chemicals of concern are widely used across California. Many townships on the interactive map are shaded red, indicating that they used more than 660,000 pounds of these chemicals between 2003 and 2012. These include the following fumigants known to be particularly harmful to human health:  

  • Chloropicrin, or "vomiting gas," originated as a chemical weapon in World War I. The gas caused soldiers to vomit and therefore remove their protective gas masks, exposing them to other toxic gases. After the war, the stockpiles of chloropicrin were used as a fumigant for certain crops, including strawberries. Chronic exposure to chloropicrin is linked to respiratory problems and other health concerns.

  • Methyl bromide is an ozone-depleting gas that has been largely phased out by the Montreal Protocol. However, the treaty includes a "critical use exemption" that allows farmers to continue to use it if no economically feasible alternatives exist. California alone uses around 90 percent of all methyl bromide applied in the developed world. Methyl bromide is highly toxic and can corrode a person's eyes and skin on contact. Chronic exposure may affect the nervous system.

1,3-dichloropropene (1,3-D) is a fumigant that is thought to cause cancer. California places a limit on the amount of 1,3-D that can be used per township (90,250 pounds per township per year):

  • Over 100 townships exceeded their annual limit of 1,3-D at least once between 2003 and 2012. For two townships, the total amount above the limit topped 1 million pounds.

  • California banned sales of 1,3-D in 1990 because of its health risks. But Dow Chemical Company produced research that supposedly refuted the chemical's risks and successfully petitioned the state to allow the company to sell 1,3-D again on a restricted basis. Dow also lobbied for loopholes that enable townships to exceed the established limit.

  • Many leading toxicologists in California disagree with Dow's scientific methods and conclusions and argue that these loopholes may increase cancer risks.

The map also demonstrates that toxic chemicals are being used within close proximity to some of California's schools. Rio Mesa High School is in a pesticide "hotspot," indicating that its surrounding townships have some of the highest rates of pesticide use. The school is surrounded by strawberry fields on all sides. Fumes from pesticide applications can drift to the school and expose its students to toxic chemicals. Additionally, growers in the area exceeded the 1,3-D limit ten out of the past 12 years. Rio Mesa's students and other California schoolchildren face unreasonably high risks of pesticide exposure just by going to school.

Addressing California's Toxic Addiction

Strawberries can be grown organically, without chemical fertilizers and pesticides, and some California growers have adopted organic methods. But farming is a risky business, and chemical fumigants help prevent diseases and pests that devastate crops. Many California growers are unwilling to take the financial risk of forgoing use of pesticides. Moreover, the high cost of land drives many growers into high-value crops like strawberries that often require heavy pesticide use to be profitable.

Meanwhile, researchers are searching for alternatives to harmful fumigants in strawberry fields. One option is to plant strawberries in coconut fiber, which does not contain as many pests as soil. But this method costs growers an additional $5,000 to $8,000 per acre, making it a costly investment.

While researchers continue to experiment with new methods, California's government must close the loopholes that allow growers to exceed limits on harmful pesticides like 1,3-D. Acceptable limits of fumigants must be based on the best available research, not industry rebuttals.

Moreover, California should create incentives for growers to adopt safer methods that eliminate the need for fumigants. This would protect workers and communities from the dangers associated with pesticide applications.

In the meantime, consumers can support organic growers by choosing organic strawberries and educate themselves more about the issue. This is especially important for those living in affected California communities. For more information, visit the Center for Investigative Reporting's Dark Side of the Strawberry landing page.

back to Blog