Apple has been evasive in addressing pollution concerns and the health issues that its workers faced while supplying parts for its gadgets, a group of 36 Chinese environmental groups said.

In a report to be published on Thursday, the group also reportedly criticised the iPad maker for not responding to NGO’s concerns over pollution and worker’s health and ranked Apple last in a list of 29 technology companies for its lackadaisical approach.

An Apple spokesman said that the company had a rigorous auditing programme that investigates its suppliers and other parts of the business supply chain.

The activist groups pointed out that Apple failed to respond to the poisoning of workers at Lianjian Technology, a subsidiary of Taiwan-based Wintek, which produces touchscreen modules for Apple’s mobile devices.

In 2009, nearly 49 workers were hospitalised for poisoning due to the chemical cleaning agent n-hexane.

The workers claimed the incident left them with debilitating illnesses and that they have not received any response to complaints they sent to Apple.

A Wintek spokesman, however, maintained that the factory has stopped using the cleaning agent immediately after the accident and has also improved working conditions at its factories.