English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

Though the Clean Air Act gives the Environmental Protection Agency considerable powers to regulate both mobile and stationary air-pollution sources directly,' everyday control of most existing stationary sources remains subject to an awkward joint federal-state program based on ambient air-quality standards.2 The core of this program is section 109, under which the EPA promulgates primary air-quality standards "requisite to protect the public health" and secondary standards "requisite to protect the public welfare from any known or anticipated adverse effects."3 Under section 110, the states then submit plans to the EPA for "attainment and maintenance" of the primary standards within three years and of the secondary standards within "a reasonable time."4

Relaxation of Implementation Plans under the 1977 Clean Air Act Amendments