Large particles from volcanic eruptions will fall out of the atmosphere rapidly but fine volcanic aerosols can travel long distances in the stable stratosphere, a layer of air extending roughly from 10-16 kilometres to 50 kilometres aloft, depending on the latitude.

It is unlikely that these aerosols, which travel long distances within the stratosphere, could serve as condensation nuclei and contribute to local rainfall which occurs in the lower part of the atmosphere, namely the troposphere, the layer of air between ground the stratosphere.

The author also claimed that the June 1991 Pinatubo eruption was a factor of the below-normal yearly rainfall in Hong Kong that year.

However, a careful examination of the monthly rainfall of 1991 would reveal that the rainfall deficit mainly occurred in spring (Mar-May) before the Pinatubo eruption.

Lee Sai-ming, acting senior scientific officer, HK Observatory

Make effort to preserve our cuisine

Florence Tang's letter ('Preserve HK's heritage lifestyle, too', April 20) hit a nerve.

Our heritage schemes should also look at preserving and protecting Hong Kong's culinary traditions the way other countries do.

France, for instance, has had the United Nations' cultural body, Unesco, officially recognise its culinary and gastronomic traditions as an intangible part of its heritage.

With our marketplaces shrinking, many of our culinary traditions are dying out with it.

Consider several other movements percolating in Hong Kong recently - organic farming in the New Territories, the rise of local gastronomic artisans, farmer's markets - and it's obvious that there's a populist desire and sentiment to reclaim our connection to the land and preserve our culinary traditions.

There's just not enough spaces and venues for this.

Hong Kong's heritage revitalisation scheme should take these intangible assets of our heritage into account and preserve them for future generations.

Anthony Tam, Sai Wan Ho

Clock ticks for quaint, lively areas

I cringe every time I walk through Wan Chai knowing how much has changed since the Urban Renewal Scheme had its way.

Once dotted with small street stalls, roadside markets and dumpling vendors, many have now moved elsewhere or closed shop.

It's just a matter of time before other quaint neighborhoods like Sheung Wan, Sai Ying Pun, Aberdeen and Shau Kei Wan suffer a similar fate in the name of urban renewal.

I wholly support the comments of Florence Tang ('Preserve HK's heritage lifestyle, too' April 20). If you're going to raze old structures, at least save our market traditions.

Unfortunately Hong Kong's urban landscape doesn't feature hawker centres like in Singapore and Malaysia, but let's at least retain some heritage buildings that showcase our unique food culture.

Annie Ang, Mid-Levels

History disappears from street

As a regular traveller along Garden Road since childhood, the beautiful heritage buildings of numbers 6 and 8 Kennedy Road always presented a delightful view.

It is therefore heartbreaking to witness their slow demolition, which began in March.

First the buildings were covered with scaffolding together with two banners in Chinese saying 'revitalisation of heritage buildings'.

As the 'revitalisation' work gradually progressed, the older heritage building began to lose its beautiful facade and wooden window panels and doors.

Then both buildings were gone, and the banner lay lamely on the ground.

The March issue of Heritage Hong Kong, the newsletter of the Antiquities and Monuments Office, said 'the government has successfully concluded agreements with several owners in heritage-cum-preservation development projects, including ... numbers 6 and 8 Kennedy Road'.

I would like to know if the demolition of the heritage buildings is allowed under such agreement and what preservation plan lies ahead.

I truly hope the office will not consider rebuilding a viable way of preservation, as we do not need more fake antiques like the Central Star Ferry Pier in our city.

Unfortunately, these two buildings do not attract as much public attention as King Ying Lei due to their more secluded location.

Nevertheless they were still precious, as they were representative of the architecture of residences of their time.

I hope that the new government will take heritage preservation more seriously.

Heritage is not just for nostalgia, but it has a real function in attracting more tourists to visit the city and bring in more revenue, let alone its cultural value to us.

Sarah Li, Mid-Levels

Sad to see little room for helper

I was saddened to read Post Magazine ('Sleek symphony', April 15) that, despite an apartment renovation costing around HK$1 million, the poor helper gets moved to a 'cupboard' in the kitchen.

Patrick Wilson, Pok Fu Lam

Create a friendlier city for elderly

Our elderly have contributed their whole lives to building a better Hong Kong so it is our obligation to introduce measures to improve their lives.

The World Health Organisation proposed the idea of an 'age-friendly city' a few years ago.

There are eight areas that need to be improved to create an age-friendly city: outdoor areas and buildings, transport, housing, social participation, social inclusion, civic participation and employment, communication and information, and community and health services.

We need to ensure that the pavements are well maintained, smooth, no-slip, are wide enough for wheelchairs, and have low kerbs that taper off to the road.

Some of the pedestrian crossing lights along Queen's Road East are also not on long enough for the elderly to cross the streets and this needs to be remedied.

The height of the steps found inside buildings and vehicles should be lowered or an extra step built in so that elderly passengers can get off the vehicles safely.

More seating should be installed along the pavements so the elderly have a place to rest.

In addition, there should be a HK$2 standard bus and MTR fare for the elderly so they can get easier access to anywhere in Hong Kong.

I've only given a few examples on how to increase the level of age-friendliness in Wan Chai, but there are many things that need to be done in order to attain our goal.

This goal can only be achieved with the collaboration of all community stakeholders.

Kenny Lee Kwun-yee, Wan Chai district councillor

Give warmer welcome to air travellers

Much has been written about Hong Kong's airport, but it lacks one of the most basic things: a warm welcome for visitors.

There are queues, queues and longer queues at the airport. What sort of a warm welcome is that?

Those visitors must think that we are a third world country which cannot afford some extra staff at the counters.

Why is this?

Poor planning? Understaffed?

Also, quite often many of the e-channels are closed and even the residents have to queue.

Why are they not all operational?

Altogether I think there is a lot the Hong Kong Immigration Department needs to do to improve their way of working at the airport.

Jan Arkesteijn, Tuen Mun