This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages) This article relies largely or entirely on a single source. Relevant discussion may be found on the talk page. Please help improve this article by introducing citations to additional sources.Find sources: "Environmental Health Perspectives" – news · newspapers · books · scholar · JSTOR (June 2022) This article may contain excessive or inappropriate references to self-published sources. Please help improve it by removing references to unreliable sources where they are used inappropriately. (June 2022) (Learn how and when to remove this template message) This article may rely excessively on sources too closely associated with the subject, potentially preventing the article from being verifiable and neutral. Please help improve it by replacing them with more appropriate citations to reliable, independent, third-party sources. (June 2022) (Learn how and when to remove this template message) (Learn how and when to remove this template message)