Impact of Wildfires on Lead Contamination in Los Angeles Soil: Current Debates and Findings

The U.S. Environmental Protection Agency (EPA) assures residents that most properties cleared by the U.S. Army Corps of Engineers show no dangerous levels of lead. This conclusion comes after soil testing was conducted on approximately 1% of homes affected by the Eaton Fire. However, skepticism remains from an independent scientist.

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The Eaton Fire of January 2025 resulted in significant destruction, impacting approximately 9,400 homes in the Altadena area and releasing harmful substances like lead, arsenic, and asbestos into the air. Lead exposure is particularly concerning due to its neurotoxic effects and potential developmental risks for children.

Post-inspection of 100 randomly selected residences by the EPA revealed that only five homes exceeded established lead safety standards. However, 17 parcels reported levels above California’s stricter regulations. The EPA report indicated that the median lead concentrations across all assessed sites remained well below both state and federal safety thresholds. The EPA news release was issued Tuesday.

This data should instill confidence in residents regarding the remediation efforts by the Corps to manage fire-related contaminants, especially lead, noted Michael Montgomery, director of EPA’s Region 9 Superfund and Emergency Management Division. “The Corps effectively removed ash, debris, and the contaminated soil beneath these materials,” he added.

Montgomery expressed belief that the findings are representative of the entire affected burn zone.

“I am 95% confident that the areas addressed in Altadena and Pasadena are below both California and federal lead inspection thresholds,” he affirmed.

The trauma of contamination fears loomed large over Altadena, where many lots were blanketed in soot and ash from the Eaton Fire, particularly concerning given the older homes — many constructed before lead was eliminated from building materials. While the Army Corps removed about two-thirds of the debris from affected sites, soil testing was not conducted as part of the cleanup effort, raising concerns among residents about lingering contamination risks.

Since soil testing was not mandated during cleanup efforts, academic scientists from the Los Angeles County Department of Public Health have initiated their own testing in the area, resulting in concerns due to mixed results.

Andrew Welton, a professor specializing in civil, environmental, and ecological engineering at Purdue University, has critiqued the EPA’s assessment as inconclusive. He noted that the methodology employed was aimed at measuring average risks, not pinpointing higher-risk areas.

Welton emphasized, “The results they obtained are not representative of the Eaton fire area,” adding that the sample collection methods were not aligned with existing data that Californians and businesses expect regarding property safety.

Critics have raised alarms about the debris removal process, where the Army Corps was reported to have inconsistently and hastily removed debris, with whistleblowers suggesting the quantity of leftover debris was higher compared to past wildfire responses. Concerns remain regarding the ongoing risk of contamination for residents.

“It’s so incomplete,” one whistleblower remarked.

Montgomery shared that the Federal Emergency Management Agency (FEMA) requested the EPA to perform testing in light of the concerns voiced by residents and officials, a protocol not typically followed in past wildfire incidents.

The EPA’s study aimed to provide a comprehensive understanding of contamination levels throughout the Eaton burn area. Properties were selected randomly, and inspections were conducted at accessible locations with resident consent.

For each site, soil samples were collected from two distinct depths at 30 specified locations within the “ash footprint” designated for debris removal.

These samples were then pooled to form two composite samples—one at ground level and another six inches below.

The findings revealed that median lead concentrations in surface soils measured at 31 milligrams per kilogram, significantly below the California threshold of 80 mg/kg and the EPA’s level of 200 mg/kg. The below-surface concentration averaged 43 mg/kg.

EPA findings indicated that five surface samples surpassed the federal testing standards, with one sample showing a lead concentration of 705 mg/kg.

Welton expressed concerns that the EPA’s approach of pooling samples could obscure contamination hotspots at specific locations within the impacted area.

Based on prior evidence in California, “hotspots” often occur post-debris removal, where contractors may have left ash and debris intact. Even properties that pass this average test might still harbor lead levels that exceed state guidelines.

Welton also noted that the EPA’s testing was limited to the volcanic ash footprint and did not account for unassessed areas of the property.

He pointed out that the most contaminated sites, averaging 705 mg/kg of lead, raise significant concerns, as levels above 1,000 mg/kg are classified as hazardous and necessitate disposal in specialized landfills.

“That means the entire property is warmer,” Welton concluded. “There could be areas with even higher contamination levels.”

Source: www.nbcnews.com

AI May Be More Persuasive Than Humans in Debates, Scientists Find

Artificial intelligence can perform tasks similarly to humans, if not more effectively, particularly in crafting persuasive arguments rather than just being unable to shout.

Experts have raised concerns about the implications this has, especially regarding the integrity of elections.

“If we can deploy persuasive AI on a large scale, we could envision an army of bots micro-targeting undecided voters with tailored political narratives that seem authentic,” he mentioned. Additionally, he pointed out that such influences are challenging to monitor, harder to regulate, and nearly impossible to detect in real time.

“It would be surprising if malicious entities hadn’t begun using these tools to disseminate misinformation and biased propaganda,” Salvi stated.

Nonetheless, he also noted that persuasive AI could have positive effects, such as reducing conspiracy beliefs and political polarization, as well as encouraging healthier lifestyle choices.

In a report featured in the Nature Human Behavior Journal, Salvi and his colleagues described an online experiment with 300 participants faced with 300 human opponents, and another 300 paired with Chat GPT-4.

Each participant was assigned a topic for discussion. Did these topics lead to debates such as “Should students wear school uniforms?” or “Should abortion be legalized?” Each participant was randomly given a stance to argue.

Before and after the discussions, participants rated their level of agreement with the proposals.

In half of the pairs, whether human or AI, additional information about the opponents, like age, gender, ethnicity, and political affiliation, was provided.

The results from the 600 discussions showed that Chat GPT-4 was as effective as its human counterparts in persuading others, provided no personal information was shared.

However, access to such personal details made the AI more convincing than humans. When both types of opponents were similarly unpersuasive, the AI was able to shift participants’ opinions 64% of the time compared to human opponents.

Upon further investigation, the team found that AI’s persuasiveness was particularly evident on topics that elicited less strongly held views.

The researchers noted that when human participants were paired with AI, they correctly guessed their partner’s identity about 75% of the time. The team also observed that AI utilized a more analytical and structured approach compared to human participants, but not all engaged in arguments they personally supported. However, the team cautioned that these aspects did not fully account for AI’s persuasiveness.

Rather, its effectiveness seemed to stem from its ability to tailor arguments to individual preferences.

“It’s akin to debating with someone who makes a compelling case,” Salvi remarked, noting that the impact could be even greater with more detailed personal information, such as insights derived from someone’s social media activities.

Professor Sander van der Linden, a social psychologist at Cambridge University who did not participate in the study, remarked that it reopened discussions about the potential for large-scale manipulation of public opinion through personalized conversations with language models.

While he indicated that various studies, including his own, have shown that the persuasiveness of language models relies on analytical reasoning and evidence use; one study revealed that personal information did not enhance Chat GPT’s persuasiveness.

Professor Michael Wooldridge, an AI researcher at Oxford University, acknowledged that while there are beneficial applications of such systems, like health-related chatbots, there are many concerning aspects as well, including the potential exploitation of these applications by harmful groups targeting youths.

“As AI continues to evolve, we will witness an increasingly broad range of potential technological abuses,” he asserted. “Policymakers and regulators must act decisively to stay ahead of these threats rather than constantly playing catch-up.”

Source: www.theguardian.com