What the papers say - August 28

Warnings over smog's impact on intelligence, allegations over foul play by schools during exam season and concerns over violent crime make headlines on Tuesday.

New research suggests air pollution is causing a "huge" reduction in intelligence, in addition to other physical health effects, The Guardian reports.

Claims that thousands of weak-performing state school pupils were excluded during GCSE exams to "game" the system lead The Times.

The i leads with an announcement by the Prime Minister that the UK aid budget will be used to help British businesses invest in Africa after Brexit.

Meanwhile, in a blow to Theresa May, French president Emmanuel Macron has ruled out Brexit compromises that risk the EU "unravelling", The Independent reports.

The Financial Times focuses on a preliminary trade deal struck between the US and Mexico that Donald Trump lauded as "incredible".

The Daily Mail leads with a report by former Tory leader Iain Duncan Smith's think-tank that calls for stop and search to be used with greater frequency to tackle gang-related violent crime.

Meanwhile the Daily Express says it has uncovered figures that show a surge in violent crime against elderly people.

The Daily Telegraph leads with allegations Labour MP Khalid Mahmood, the shadow Europe minister, used taxpayer money to gag a Jewish assistant.

A police sergeant is suing senior officers for £250,000 after he came under fire from live bullets during a training exercise, according to The Sun.

The Daily Mirror leads with warnings that extreme winter and summer weather will push up food prices.

The scorching weather has also hit pig farmers, driving up the price of bacon, the Daily Star reports.