How choosing the right house plant can improve indoor air quality
Bromeliads from the pineapple family can remove more than 80 per cent of harmful volatile organic compounds from indoor air, laboratory tests show. PLUS: why dead-end jobs will get you down
If you are looking for a cheap and efficient way to improve the quality of the air you breathe indoors, try putting a few pots of the bromeliad plant in your office or home. According to a new study, this type of plant – which has over 2,700 described species, the most well known being the pineapple – is very good at removing more than 80 per cent of volatile organic compounds (VOCs) from the air.
The finding comes from tests involving five common house plants and eight common VOCs – compounds such as acetone, benzene and formaldehyde that are emitted as gases and can cause short- and long-term harm to health when inhaled. VOCs can come from paints, furniture, copiers and printers, cleaning supplies and even dry-cleaned clothes.
Certain plants are better at absorbing specific compounds, according to the researchers. For example, all five plants tested can remove acetone – the pungent chemical that is abundant in nail salons – from the air, but the dracaena plant took up the most, around 94 per cent of the chemical.
WATCH: Indoor air pollution explained
“Buildings, whether new or old, can have high levels of VOCs in them, sometimes so high that you can smell them,” says study leader Vadoud Niri of the State University of New York at Oswego. “Inhaling large amounts of VOCs can lead some people to develop sick building syndrome, which reduces productivity and can even cause dizziness, asthma or allergies.”
The most common solution is to install ventilation systems that cycle in air from outside. There are also means of removing these compounds, using adsorption, condensation and chemical reactions. House plants, however, are a much cheaper and simpler tool, as tests on these five plants showed:
1. Bromeliad (Guzmania lingulata)
The best at removing benzene (92 per cent over the 12-hour study period), a toxic gas present in motor vehicle exhaust and cigarette smoke. It was also the most effective, overall, at removing multiple VOCs – taking up more than 80 per cent of six out of the eight chemicals studied.
2. Dracaena (Dracaena frangas)
All five plants did a good job removing acetone (the pungent chemical present in nail polish remover), but Dracaena plant did the best job (94 per cent).
3. Jade plant (Crassula argentea)
This plant was best at removing toluene (91 per cent), a strong-smelling chemical often associated with paint thinners.
4. Spider plant (Chrolophytum comosum)
This plant was best at removing ethylbenzene (62 per cent), p-Xylenes (92 per cent), and o-Xylene (93 per cent) – chemicals found in inks, rubbers, adhesives, paints and varnishes.
5. Caribbean tree cactus (Consolea falcata)
While not the best performer in any area, this plant removed more than 80 per cent of ethylbenzene, p-Xylenes and acetone, and about 60 per cent of benzene, toluene, and o-Xylene.
Niri says the next step in the research is to test these plants’ abilities in a real room, not just a sealed chamber. He would eventually like to put plants in a nail salon over the course of several months to see whether they can reduce the levels of acetone that workers are exposed to.
Stuck in a dead-end job? It’ll start getting you down once you turn 40
Job satisfaction when you are in your late twenties and thirties has an effect on your health in your early forties, according to a new nationwide study in the United States. While job satisfaction had some impact on physical health, its effect was particularly strong on mental health, researchers at Ohio State University have found. Those less than happy with their work early in their careers said they were more depressed and worried and had more trouble sleeping.
“We found that there is a cumulative effect of job satisfaction on health that appears as early as your forties,” said Jonathan Dirlam, lead author of the study and a doctoral student in sociology at The Ohio State University.
The researchers used data from 6,432 Americans who participated in the National Longitudinal Survey of Youth 1979, which followed adults who were between the ages of 14 and 22 when the survey began in 1979. The researchers examined job satisfaction trajectories for people from age 25 to 39. These participants then reported a variety of health measures after they turned 40.
Participants rated how much they liked their jobs from 1 (dislike very much) to 4 (like very much). About 45 per cent of participants had consistently low job satisfaction, while another 23 per cent had levels that were trending downward through their early career. About 15 per cent of people were consistently happy at their jobs (nearly 4 on the scale of 4) and about 17 per cent were trending upward.
Using those who were consistently happy as the reference, the researchers compared how the health of the other three groups compared. People who were in the low job satisfaction group throughout their early careers scored worse on all five of the mental health measures studied. They reported higher levels of depression, sleep problems and excessive worry. They were also more likely to have been diagnosed with emotional problems and scored lower on a test of overall mental health.
Those whose job satisfaction started out higher but declined through their early career were more likely than those with consistently high satisfaction to have frequent trouble sleeping and excessive worry, and had lower scores for overall mental health. But they didn’t see an impact on depression scores or their probability of being diagnosed with emotional problems.
Those whose scores went up through the early career years did not see any comparative health problems.
The physical health of those who were unhappy with their jobs wasn’t impacted as much as mental health. Those who were in the low satisfaction group and those who were trending downwards reported poorer overall health and more problems like back pain and frequent colds compared to the high satisfaction group. But they weren’t different in physical functioning and in doctor-diagnosed health problems such as diabetes and cancer.
“The higher levels of mental health problems for those with low job satisfaction may be a precursor to future physical problems,” says co-researcher Hui Zheng, an associate professor of sociology. “Increased anxiety and depression could lead to cardiovascular or other health problems that won’t show up until they are older.”
Children should eat less than 25 grams of added sugar a day
Children over two years old should eat or drink less than six teaspoons of added sugar daily, according to the latest scientific statement recommending a specific limit on added sugar for children, published in the American Heart Association journal Circulation. Six teaspoons of added sugar is equivalent to about 100 calories or 25 grams.
The statement was written by a panel of experts who did a comprehensive review of scientific research on the effect of added sugar on children’s health.
“Our target recommendation is the same for all children between the ages of two and 18 to keep it simple for parents and public health advocates,” says Dr Miriam Vos, lead author, nutrition scientist and associate professor of paediatrics at Emory University School of Medicine in Atlanta, Georgia.
“For most children, eating no more than six teaspoons of added sugars per day is a healthy and achievable target.”
Eating foods high in added sugar throughout childhood is linked to the development of risk factors for heart disease, such as an increased risk of obesity and elevated blood pressure in children and young adults.
“Children who eat foods loaded with added sugars tend to eat fewer healthy foods, such as fruits, vegetables, whole grains and low-fat dairy products that are good for their heart health,” says Vos.
The likelihood of children developing these health problems rises with an increase in the amount of added sugars consumed. Overweight children who continue to take in more added sugars are more likely to be insulin resistant, a precursor to type 2 diabetes, according to the statement.
The typical American child consumes about three times the recommended amount of added sugar, Vos notes. Added sugars are any sugars – including table sugar, fructose and honey – either used in processing and preparing foods or beverages, added to foods at the table or eaten separately.
The expert panel recommends that added sugar should not be included at all in the diet of children under the age of two. The calorie needs of children in this age group are lower than older children and adults, so there is little room for food and beverages containing added sugars that don’t provide them with good nutrition. In addition, taste preferences begin early in life, so limiting added sugars may help children develop a lifelong preference for healthier foods.
Note: This report was amended on September 2 to add an animation explaining indoor air pollution and, in response to a reader’s comment, include the names of the five plants tested and their pollution-reducing properties.