LCQ14: Plants planted in public placesFollowing is a question by the Hon Cheung Hok-ming and a written reply by the Secretary for Development, Mrs Carrie Lam, in the Legislative Council today (December 7):
It has recently been reported that some plants planted by some of the outsourced service contractors of the Leisure and Cultural Services Department in public places fall into the list of 52 cancer-causing plant species announced by the Chinese Centre for Disease Control and Prevention, and if members of the public are in frequent contact with these plants, the carcinogens in the plants may cause cells to become cancerous. In this connection, will the Government inform this Council:
(a) whether the government departments concerned keep a register or a list of plants which have negative health impacts on humans and animals; if they do, of the relevant details;
(b) whether the government departments concerned have provided guidelines to their outsourced service contractors, so as to avoid planting in public places plants which pose health hazards to humans and animals; if they have, of the details, and how they monitor compliance with the guidelines by the outsourced service contractors; if they have not, whether they will conduct a review of the present policy, so as to formulate appropriate measures to safeguard the health of the public and animals;
(c) whether plants which fall into the aforesaid list of 52 cancer-causing plant species have been planted in the public places managed by government departments and the Hospital Authority at present; if so, of the distribution of their locations, quantities and species; and
(d) how it will step up publicity and education so that the public will avoid coming into contact with these carcinogenic plants?
To enhance the living environment, the Government takes meticulous care in selecting the plants for planting as well as their maintenance. We also organise public education and community involvement activities to enlist public support for the greening works and foster a culture of caring for plants.
My reply to the four parts of the question is as follows :
(a) In selecting plants, departments follow the principle of planting "the right species in the right place" and take into account a number of factors, including the design and works requirements (eg design concept, costs of works, etc.), environmental factors (eg soil quality, impact on sightline and traffic, etc.), and characteristics of the plant species (eg drought tolerance, toxicity, etc.). In general, the departments will avoid planting plants with poisonous features in parks or other locations that are easily accessible to the public.
The Plant Selection Matrix in the Landscape Standards and Guidelines, compiled by the Leisure and Cultural Services Department, provides a checklist on the features of common landscape plants, including their poisonous parts, if any. The Check List of Hong Kong Plants and The Flora of Hong Kong, compiled by the Agriculture, Fisheries and Conservation Department (AFCD), also sets out features of plants commonly seen in Hong Kong, including their habitat, distribution, ecology and medicinal effects/toxicity. These publications provide useful references for departments in selecting suitable plants and identifying the toxicity of different plants.
Although certain plants have poisonous parts, they do not spread its toxicity through the air. Thus, the poison in these wild or landscape plants cannot easily enter into the human body and cause harm except through prolonged direct contact with, picking or ingesting them.
(b) In drawing up planting plans, departments will consider the factors as mentioned above and avoid planting species with poisonous features in parks or other places that are easily accessible by the public. Landscape contractors are required to comply with these planting plans in undertaking the landscape works. The completed works are also subject to works inspection by relevant departments before acceptance. Given that the landscape contractors are required to comply with the planting plans drawn up by departments when undertaking the landscape works, the Government has not issued separate guidelines on selection of plant species for landscape contractors.
To further assist the departments in selecting suitable plants, the Greening, Landscape and Tree Management Section under the Development Bureau has commissioned a consultancy study for developing a more comprehensive set of criteria on plant species selection.
(c) We have combed through publications of studies on the relationship between plants and cancer conducted in recent years for the concerned "list of cancer-causing plant species". We could only locate a publication on a similar subject by Mr Zeng Yi et al of the Institute of Virology, China Institute of Preventive Medical Science in the Chinese Journal of Virology in June 1992, which reported on an in vitro experiment conducted in laboratory settings to study the impact of concentrated extract from different herbs and plants on a group of cells. This experiment was conducted in settings that were entirely different from the environment where people come into contact with plants in their daily lives. Therefore, the Government has not sought to keep records on the quantity and distribution of locations of the species covered in that study.
(d) The AFCD has published a leaflet on The Five Most Poisonous Plants in Hong Kong, cautioning the public against contact with, picking or ingesting these highly poisonous plants commonly found in the countryside of Hong Kong. The then Urban Council also published a book on Hong Kong Poisonous Plants. We will extract relevant information from the book and upload this to our Greening Website for public information. In the meantime, we will also closely monitor the situation and keep the public informed if any commonly found plants or popular landscape plants are confirmed to be harmful to human bodies.
Ends/Wednesday, December 7, 2011
Issued at HKT 15:43