One metres or two? Or is it six? When it comes to coronavirus social distancing, there is no single rule of thumb, researchers cautioned this week in a study.
Indoors or outside; the velocity and pattern of air flows; whether one is whispering, shouting or sneezing; air conditioning or open windows; duration of exposure; whether one is wearing a mask all of these elements will determine how far is far enough when it comes to steering clear of Covid-19 infection.
"Rigid safe distancing rules are an oversimplification based on outdated science and experiences of past viruses," said lead author Nicholas Jones, a researcher at Saint Thomas Hospital in London.
"Instead of single, fixed physical distance rules, we propose graded recommendations that better reflect the multiple factors that combine to determine risk."
Around the world, living with Covid-19 has become a reality.
A widely available vaccine is months away at best, and the number of cases is on the rise again in many countries that had succeeded in bringing the epidemic under control.
But governments at all levels eager to avoid the lockdowns that devastated their economies are looking for ways to fine-tune policy responses in a middle ground.
On Thursday, for example, France's prime minister flanked by his ministers of education and health outlined new measures that included mandatory mask wearing in Paris and its immediate suburbs, among other regions.
Previously, masks had been obligatory only in public transport, shops, and public buildings.
- Low- and high-risk scenarios -
From the earliest days of the pandemic, experts have sharply debated what constitutes "safe" social distancing.
The World Health Organization (WHO) recommends "maintaining at least one metre (three feet) distance between yourself and others," and many national health authorities have issued similar guidelines.
But experiments conducted in recent months suggest this may still be too close for comfort, at least in some circumstances.
"Eight out of 10 studies in a recent systematic review showed horizontal projection of respiratory droplets beyond two metres for particles up to 60 microns," Jones and colleagues noted in the BMJ, a medical journal.
In one study, droplets that could contain live virus were detected more than six metres from the source, a distance consistent with sneezing, coughing or vigorous singing.
These findings could explain the case of a choir practice in the United States in which a person carrying the SARS-CoV-2 virus infected 32 other singers with 20 other likely cases despite physical distancing.
Sports clubs, boxing or martial arts gyms, churches, call centres are all places where people sing, pant or talk loudly.
Interestingly, there have been few 'super-spreader' incidents on commercial flights, perhaps because people don't talk much and are more likely to be wearing masks, the authors speculated.
How far a virus might spread in an indoor setting is also determined by whether the air in a room is ventilated with open windows or recirculated with an air conditioning system.
The density of occupation is likewise key.
Taking all these factors into account, Jones and his team devised a chart which could also serve as a guide to measure risk in different situations.
If you are speaking quietly in a well-ventilated, sparsely-populated office space while wearing a face mask, for example, risk is minimal.
The same scenario without a face mask, or in a crowded office, translates into a higher but still moderate degree of risk.
Shouting or singing in a poorly ventilated room without wearing a mask, however, would put one squarely in the red zone, the study
AFP RELAXNEWS
Sat Aug 29 2020
Wearing a face mask can minimise the risk of getting infected.
Freedom Flotilla to Gaza: Guinea-Bissau akur kepada Israel, tidak beri kebenaran guna bendera bagi misi pelayaran
Kerajaan Republik Guinea-Bissau dilaporkan tunduk dan akur kepada gesaan Israel untuk tidak membenarkan misi pelayaran Break The Siege: Freedom Flotilla to Gaza menggunakan bendera mereka.
Penyakit berkaitan haba dikhuatiri meningkat di Gaza
Penularan penyakit berkaitan haba panas menjadi kebimbangan terbaharu di Gaza selepas suhu luar jangka melampau melanda wilayah itu setiap hari. Ia sudah semestinya diburukkan lagi dengan kekurangan air bersih dan ketiadaan sistem pembuangan sisa pepejal yang sepatutnya wujud di sesebuah kawasan didiami manusia.
Ilhan Omar melawat peserta tunjuk perasaan
Wakil Dewan Perwakilan Amerika Syarikat (AS) Ilhan Omar mengadakan lawatan di kampus penyokong Pro Palestin di Universiti Columbia New York pada Khamis.
Dua lelaki didakwa jadi 'tali barut' kepada China
Dua lelaki yang mana salah seorangnya pernah bertugas di Parlimen United Kingdom (UK) enjalani proses perbicaraan di mahkamah London pada Jumaat selepas didakwa menjadi tali barut menyalurkan maklumat sulit kerajaan kepada negara tembok besar itu.
Polis serbu pejabat 'Save the Children' di Guatemala
Polis Guatemala melakukan serbuan mengejut ke atas pejabat-pejabat Pertubuhan Save the Children di pelbagai lokasi di negara itu. Ia bagi mencari bukti dakwaan pertubuhan yang memperjuangkan kebajikan kanak-kanak itu, terlibat dalam jenayah penderaan terhadap golongan itu.
LIMA '25 dianjurkan pada 20-24 Mei tahun depan
Pameran Maritim dan Aeroangkasa Antarabangsa Langkawi 2025 (LlMA ‘25) akan dianjurkan pada 20 hingga 24 Mei tahun depan bertemakan Innovate Today, Thrive Tomorrow.
Malaysia komited tingkat hubungan dua hala bersama Libya
Malaysia terus komited mempertingkatkan hubungan dua hala yang berterusan bersama Libya demi manfaat bersama dalam pelbagai sektor.
Demi rakyat, Zahid-Muhyiddin henti saman fitnah
Presiden Umno, Datuk Seri Ahmad Zahid Hamidi dan Presiden Bersatu, Tan Sri Muhyiddin Yassin bersepakat untuk menamatkan pertikaian peribadi antara mereka.
Sultan Selangor berangkat ke Majlis Bacaan Yassin di Pangkalan TLDM
Sultan Selangor Sultan Sharafuddin Idris Shah yang juga Kepten Yang Dipertua Tentera Laut Diraja Malaysia (TLDM) berkenan berangkat ke Pangkalan TLDM Lumut di Perak bagi menghadiri Majlis Bacaan Yasin, Tahlil dan Khutbah Khas sempena Sambutan Hari TLDM ke-90.
PM Anwar pulangkan elaun Pengerusi Khazanah
Perdana Menteri Datuk Seri Anwar Ibrahim memaklumkan beliau memulangkan elaun sebagai pengerusi Khazanah Nasional Berhad yang diterimanya dan sekali lagi menegaskan tidak menerima gaji bagi jawatan Perdana Menteri yang disandangnya sejak November 2022.
Semua empangan di Selangor berkapasiti penuh, mampu bertahan empat bulan
Secara keseluruhan, kapasiti air mentah mampu bertahan selama tempoh empat bulan tanpa hujan.
Masalah air perlukan penyelesaian yang lebih saksama
Jelas beliau, jika masalah air ini gagal diatasi ia juga akan menyumbangkan kepada penutupan kilang-kilang dan pelabur berpindah ke negara lain.
Dasar Air Negara diperkemas, KASA lantik UKM jalankan kajian
Pakar runding dari Universiti Kebangsaan Malaysia (UKM) dilantik Kementerian Alam Sekitar dan Air bagi menjalankan kajian Dasar Negara dalam mengukuhkan dasar air yang lebih menyeluruh dan holistik.
Ketika banjir melanda, LRA Cheras Batu 11, Langat 2 dihenti tugas, jejas 472 kawasan - Air Selangor
Berikutan peningkatan paras air sungai yang mengakibatkan banjir, dua LRA iaitu LRA Cheras Batu 11 dan LRA Langat 2 dihenti tugas manakala LRA Sungai Langat beroperasi pada pengeluaran separa.
Bekalan air terjejas kerana elektrik terputus - AKSB
Bekalan air terawat yang terjejas di beberapa jajahan di Kelantan berpunca dari bekalan elektrik yang terputus hingga menyebabkan pam air mentah terhenti pada Jumaat lepas.
Euro 2020: Ronaldo tolak tepi minuman tajaan kejohanan
Cristiano Ronaldo mengetepikan botol tersebut dan menyebut 'agua', sekali gus memberikan mesej kepada semua supaya tidak mengambil minuman yang mengandungi gula yang tinggi itu.
Lubang benam gergasi 'muncul' di Mexico
Lubang itu pada mulanya hanya berukuran lima meter namun saiznya menjadi berkali ganda hanya dalam beberapa jam.
Indeks Harga Pengguna naik 1.7 peratus pada Mac 2021
Peningkatan dalam keseluruhan IHP tersebut didorong oleh kenaikan indeks pengangkutan, makanan, pelbagai barangan dan perkhidmatan.
Ramadan 2021: Masalah mulut berbau.. Apa puncanya?
Ramai salah anggap, samakan plak dengan makanan yang tertinggal dalam mulut, sedangakan ia adalah benda yang bebeza.
Kerja penyenggaraan berjadual pastikan bekalan air berterusan - Air Selangor
Kerja-kerja penyenggaraan secara berjadual untuk beberapa aset utama Pengurusan Air Selangor Sdn Bhd (Air Selangor), akan dilaksanakan pada tahun ini bagi memastikan pengguna mendapat perkhidmatan bek