Tag Archives: chemicals pollution

Under Chemical Attack: the Human Body

The European Food Safety Authority (EFSA) has proposed reducing by a factor of 100,000 the tolerable daily intake of bisphenol A (BPA), an endocrine disruptor that interferes with hormone systems and has been linked to disease. The huge reduction could lead to a de facto ban on the cheap and durable material in food-related uses, such making plastic water bottler or lining metal cans. And it could mark a shift in how European regulators use research findings in setting exposure limits. Traditionally, those limits have been shaped by large studies directly linking a chemical to an increased risk of disease. In this case, however, risk assessors put greater weight on smaller studies showing low levels of BPA can cause subtle changes that could lead to future health problems. This approach, if adopted widely, could justify much lower exposure limits for other chemicals.

“It’s a big deal,” says Laura Vandenberg, an endocrinologist at the University of Massachusetts, Amherst, who calls the proposed limit “a gravestone for BPA in Europe.” Environmental and public health advocates are praising the proposal, which is open for comment until 22 February. Industry groups, however, are dismayed. Plastics Europe argues EFSA ignored relevant, older studies in setting the standard…

Bisphenol A is used in many plastics, including thermal paper for receipts, but most people are exposed through food. BPA leaches out of polycarbonates used to make bottles and food containers, for example, as well as the epoxy liners used to protect steel and aluminum cans from acidic food and beverages….

In the United States, a number of groups recently urged FDA to follow EFSA’s lead and consider new limits on BPA. Others note that people are often exposed to BPA in combination with other chemicals, which could increase the risk from low doses. F

Even if Europe adopts the new standard, public health advocates worry manufacturers will replace BPA with very similar chemicals, such as bisphenol S (BPS), that have also been linked to health effects. “We don’t want to see this assessment repeated for the BPS or BPF [bisphenol F] and need more decades of risk assessment,” says Ninja Reineke, head of science at the CHEM Trust, an advocacy group that focuses on environmental and health impacts of endocrine disruptors.

To avoid that problem, many advocates have called for regulators around the world to set limits for whole classes of related compounds, rather than consider them one by one. For now, Vandenberg says, regulators are simply playing “chemical whack-a-mole.”

Excerpts from Erik Stokstad, Europe Proposes Drastic Cut of Endocrine Disruptor in Plastic, Science, Feb, 18, 2022, at 708

How to Make Carbon-Negative Chemicals

Bacteria engineered to turn carbon dioxide into compounds used in paint remover and hand sanitiser could offer a carbon-negative way of manufacturing industrial chemicals.

Michael Köpke at LanzaTech in Illinois and his colleagues searched through strains of an ethanol-producing bacterium, Clostridium autoethanogenum, to identify enzymes that would allow the microbes to instead create acetone, which is used to make paint and nail polish remover. Then they combined the genes for these enzymes into one organism. They repeated the process for isopropanol, which is used as a disinfectant.

The engineered bacteria ferment carbon dioxide from the air to produce the chemicals. “You can imagine the process similar to brewing beer,” says Köpke. “But instead of using a yeast strain that eats sugar to make alcohol, we have a microbe that can eat carbon dioxide.” After scaling up the initial experiments by a factor of 60, the team found that the process locks in roughly 1.78 kilograms of carbon per kilogram of acetone produced, and 1.17 kg per kg of isopropanol. These chemicals are normally made using fossil fuels, emitting 2.55 kg and 1.85 kg of carbon dioxide per kg of acetone and isopropanol respectively.

This equates to up to a 160 per cent decrease in greenhouse gas emissions, if this method were to be broadly adopted, say the researchers. The technique could also be made more sustainable by using waste gas from other industrial processes, such as steel manufacturing.

Excerpt from Chen Ly, Engineered bacteria produce chemicals with negative carbon emissions, New Scientist, Feb. 21, 2022

Are We Transgressing the Planetary Boundaries?

There are an estimated 350,000 different types of manufactured chemicals on the global market. These include plastics, pesticides, industrial chemicals, chemicals in consumer products, antibiotics and other pharmaceuticals….The rate at which these pollutants are appearing in the environment far exceeds the capacity of governments to assess global and regional risks, let alone control any potential problems..

In 2009, an international team of researchers identified nine planetary boundaries that demarcate the remarkably stable state Earth has remained within for 10,000 years – since the dawn of civilization. These boundaries include greenhouse gas emissions, the ozone layer, forests, freshwater and biodiversity. The researchers quantified the boundaries that influence Earth’s stability, and concluded in 2015 that four boundaries have been breached. But the boundary for chemicals was one of two boundaries that remained unquantified.

This new research takes this a step further. The researchers say there are many ways that chemicals and plastics have negative effects on planetary health, from mining, fracking and drilling to extract raw materials to production and waste management.

Some of these pollutants can be found globally, from the Arctic to Antarctica, and can be extremely persistent…Global production and consumption of novel entities is set to continue to grow. The total mass of plastics on the planet is now over twice the mass of all living mammals, and roughly 80% of all plastics ever produced remain in the environment. Plastics contain over 10,000 other chemicals, so their environmental degradation creates new combinations of materials – and unprecedented environmental hazards. Production of plastics is set to increase and predictions indicate that the release of plastic pollution to the environment will rise too, despite huge efforts in many countries to reduce waste.

Excerpt from Safe planetary boundary for pollutants, including plastics, exceeded, say researchers, Stockholm Resilience Center Press Release, Jan. 18, 2022

For an alternative view on planetary boundaries see NY Times Article, 2015