San Diego County air purifier initiative reaches 10,000 deliveries in South Bay neighborhoods affected by odors

Milestone reached after program launch in early 2025

San Diego County’s Air Improvement Relief Effort (AIRE) program has delivered more than 10,000 air purifiers to households in the South Bay, marking a key milestone in a county response to recurring hydrogen sulfide odors linked to transboundary wastewater impacts near the Tijuana River Valley.

The program began in February 2025 and targets eligible addresses in neighborhoods including Otay Mesa West, San Ysidro, Egger Highlands, Nestor and the Tijuana River Valley, as well as the city of Imperial Beach. Distribution has been limited to one purifier per household, with priority consideration for homes with children, residents 65 and older, and communities closest to the river valley.

What residents receive and what the devices are designed to do

Participating households receive a portable air purifier and up to two replacement filters. The replacement filters include activated carbon and potassium permanganate, materials intended to reduce certain compounds in indoor air associated with nuisance odors and exposures, including hydrogen sulfide.

Program materials describe the effort as an interim measure intended to reduce indoor impacts while broader infrastructure and cross-border pollution issues continue to be addressed by multiple agencies.

• Eligibility is based primarily on residential address within defined South Bay boundaries.
• Applicants may be asked for proof of residency in some cases.
• Not all applicants are guaranteed a unit due to limited quantities.

Additional funding approved to extend distribution

County air regulators have approved an additional $1 million to continue the AIRE program beyond the initial 10,000 deliveries. The added allocation is expected to cover roughly 3,500 additional air purifiers for eligible households.

Program administrators have also reported conducting a household survey during summer 2025 among recipients; most respondents reported the purifiers helped reduce odors indoors.

Why South Bay air quality remains a persistent concern

Hydrogen sulfide is a colorless gas commonly associated with a “rotten egg” smell and can be generated when wastewater and sewage break down. In recent years, odor complaints in communities near the Tijuana River Valley have intensified, adding to long-running concerns about cross-border flows and localized pollution pathways.

County officials have framed the purifier distribution as a practical step aimed at reducing indoor impacts for residents experiencing repeated odor events.

Separately from purifier distribution, local air regulators maintain tools to help the public track hydrogen sulfide conditions and receive alerts during elevated readings, intended to support decisions that may reduce exposure during peak events.