Shenzhen Hygiene Supervision Office (SHSO) has called for caution over the likely increase of contaminated vegetables in hot and damp weather.

An inspection by SHSO last week found eight of 30 samples of vegetables were contaminated with organic phosphorus. The vegetables tested mainly came from the major wholesale markets and some restaurants and supermarkets.

The contaminated vegetables found by SHSO involved common vegetables such as Chinese white cabbage, cabbage mustard, water spinach and lettuce.

SHSO said the low pass rate of 73.33 percent was due to the high temperatures and continuous rain that stimulated the use of farm chemicals to curb insects.

Normally the pass rate is around 90 percent, according to SHSO. However, some experts said there was no need for concern as the number of samples was too small to obtain a meaningful result.

Organic phosphorus can cause damage to the nervous system. Experts with SHSO suggest people wash carefully all vegetables in three steps during summer.

First, wash them in cold water, then soak them in clean water for about 15 minutes. The last step is to wash the vegetables in hot water before cooking them. The used water must then be discarded. It must not be used to make soup.

Editor: Wings