Every day on Page 2 of The Straits Times, reporters write about why certain news reports matter to readers. This is a weekly round-up of the columns.

The National Environment Agency (NEA) introduced new bandings and descriptors for the one-hour concentration readings of fine particles called PM2.5 earlier this week. Reporter Carolyn Khew welcomed the move as the descriptors will help people plan their activities so as to reduce exposure to the particles. http://str.sg/4wvN

Credit rating agencies have shredded Britain's triple-A rating after Brexit. This could have serious consequences, making it more expensive for Britain to borrow, said Deputy Business Editor Aaron Low. This could cripple the British economy, given that it faces a growing budget deficit and is likely to enter into recession. http://str.sg/4wVS

The case of the five missing booksellers in Hong Kong has exacerbated the territory's distrust of the central government. Senior Regional Correspondent in Hong Kong Li Xueying said Beijing has recognised the discomfort in Hong Kong. http://str.sg/4wzU

Malaysia's ruling party Umno sacked former deputy prime minister Muhyiddin Yassin and former Kedah chief minister Mukhriz Mahathir on June 24. Malaysia Correspondent Trinna Leong observed that Prime Minister Najib Tun Razak must have been emboldened by recent election victories to consolidate his grip on power and act against dissenters. http://str.sg/4w6s

The Singapore Exchange has laid down new rules for listed firms to annually review their sustainability. Reporter Jacqueline Woo said this is a welcome move in the right green direction as many developed markets have already included sustainability reporting in regulations. http://str.sg/4whR