Thursday, July 12, 2018

POP(s) – and we are not talking about a music genre

By Juliana Leonel
English edit: Katyanne M. Shoemaker

Persistent organic pollutants, commonly known as POPs, are a group of compounds that are very resistant to degradation. These compounds bioaccumulate, can be transported far from their source through atmospheric and oceanic currents, and can have adverse impacts on living organisms, including humans.

In 2001, representatives from various countries signed an agreement called the Stockholm Convention with the aim of reducing and controlling the production and use of POPs. This treaty went into effect in 2004 with 151 signatory countries. Initially, 12 compounds were classified as POPs, and the participating countries agreed to ban the use of nine of them. Additionally, the use of DDT (we have a post on DDT here) was limited to only malaria control, and the unintentional production of dioxins and furans was to be reduced.

The first 12 POPs were all organochlorine compounds (organic compounds formed by C, H, and Cl), which were divided into three groups according to their use and production. The first group consists of pesticides and herbicides: compounds used to fight agricultural pests such as insects and weeds, which are harmful to the production or storage of grains, fruits, vegetables, wood, etc. The second group includes compounds used in industrial processes, such as polychlorinated biphenyls (PCBs) that were mainly used to cool engines, generators, and transformers. Finally, the third group consists of the dioxins and furans, which are compounds unintentionally produced by some industrial processes. This third group contains  by-products of processes (e.g. metallurgy and steel manufacture) and are not produced for a specific purpose. Over the years, during the Conference of the Parties, another 17 compounds or groups of compounds have been added to the list of POPs.

From left to right: o,p'- DDT, cis-chlordane, PCB 153, perfluorooctane sulfonate, PBDE99

To deal with each of these compounds, they were classified into three annexes. Annex A: compounds that must have their use and production eliminated; Annex B: compounds whose use and production should be restricted and only allowed in specific cases; and Annex C: compounds in which (unintentional) production must be controlled and, where feasible, must be phased out.

Each signatory country is responsible for carrying out inventory of stocks, production, and use of POPs in its territory. In addition, these countries must implement measures to reduce or eliminate the release of both intentionally and unintentionally produced POPs. In some cases, it is possible to request an exemption, to use one of the POPs in exceptional cases for a pre-determined amount of time (Ex: DDT use in case of malaria infestations). Signatory parties are also responsible for conducting systematic monitoring studies to assess whether measures are being effective in reducing the environmental levels of POPs.

Brazil approved the Convention’s text through Legislative Decree No. 204 on May 7th, 2004, and promulgated it via Decree No. 5472, on June 20th, 2005. Implementation of the Convention in Brazil is coordinated by the Ministry of the Environment (MMA) through the Secretary of Water Resources and Environmental Quality.

Although POPs are mainly used on land, their transport to the ocean is quite effective, whether through atmospheric transport, urban drainage, or effluent released directly into coastal regions. In this way POPs have been detected in a wide variety of environments and animals (water, air, soil, sediment, birds, fish, marine mammals, etc.). They have been found at the peak of great mountains and in the depths of the oceans, from the equatorial region to polar regions (see an example here:  POPs are a not-so-subtle reminder that environmental contamination has no borders, and it is a problem and responsibility of all the world’s citizens. 

Stockholm Convention Text:
Stockholm Convention - Brazil - MMA
Stockholm Convention Home Page:

Friday, June 22, 2018

Big Bang to the Dawn of Life: A Brief History - Part II and III

Part II: Ideal conditions for the origin of life (as we know it)

Artist's conception of early Earth. Font
Earth's first 400 million years were hostile and desolate: temperatures of over 200 oC liquefied the crust, and volcanic gases, especially CO2, were released in large quantities into the forming atmosphere. As the Earth cooled, the crust solidified and the lower temperature allowed liquid water to remain on the surface. This cooling was a key factor in the emergence of life.
In addition, organic molecules, generated in the nebula that gave rise to our solar system, underwent chemical reactions. This resulted in more complex organic molecules, composed especially of Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus and Sulfur. These were the building blocks for the first biological molecules.
Another important event that allowed the development of life was our planet’s impact with a celestial body the size of Mars, which resulted in the formation of our Moon. It is curious to think that a collision with 100 million times more energy than the impact that killed the dinosaurs was pivotal in the establishment of life on our planet. The gravitational force of the newly formed Moon stabilized the incline of the Earth's axis. Without this stability, major climatic changes would occur, and complex life forms would likely not have developed.

Origin of the Moon: Artist's conception. Font
Other features of our planet were also fundamental to the emergence and maintenance of life, including the presence of a metallic nucleus, which generates a magnetic field and acts as a protective shield against cosmic radiation. Additionally, the presence of a mantle and its movement below the crust promotes tectonic activities such as volcanism and continental shift. Volcanism was very important in the emergence of life, since its gaseous emissions provided the compounds (CO2, H2S, etc.) that may have been used for energy by the first unicellular organisms. Volcanoes also help maintain the planet's climate and help recycle carbon back to living organisms.

Part III: Our chemical origins: the formation of biomolecules

An incredibly rare set of conditions (see Part II) allowed life to arise on our planet from organic molecules and chemical reactions. Today, all of Earth’s living organisms are composed of biomolecules such as proteins, nucleic acids, polysaccharides and lipids.
These biomolecules consist of small units interconnected with one another, called monomers. The biomonomers that form proteins, nucleic acids (DNA and RNA) and polysaccharides are respectively the amino acids, nucleotides and monosaccharides. We now know that most biomonomers can be produced spontaneously when given the necessary conditions.

Miller-Urey experiment, 1953. Font
One of the first attempts to produce biomolecules in the laboratory was done by Stanley Miller and Harold Urey in 1953. They were based on studies conducted by Alexander Oparin and J.B.S. Haldane who suggested that biomolecules and life would have emerged in a “primordial soup,” an atmosphere rich in methane, ammonia, hydrogen, and water vapor.

The Miller-Urey experiment attempted to simulate these primitive Earth conditions described by Oparin-Haldane. In a sealed system, gases were introduced to create the primitive atmosphere described above, a heat source and liquid water were added, as well as electric discharges. Under these conditions, a number of biomonomers, such as the amino acids glycine and alanine, and other organic compounds such as urea and formic acid were produced.
Although recent studies indicate that the composition of the primitive atmosphere was not exactly as Oparin and Haldane proposed, the importance of Miller-Urey's experimental results revolutionized our concept of the origin of life by solidifying the idea of a chemical origin for all living organisms.

Types of biomolecules. Font

The next step in the emergence of the first living cells was the polymerization of these small structural biomonomers. How did  amino acids, monosaccharides and nucleotides form protein chains, polysaccharides, or the complex structure of DNA and RNA? Unfortunately we still do not have all of the answers to these questions, and the hypotheses that have been developed are difficult to test.
An important question when discussing the origin of life is how these biomolecules clustered together to form the first living cells capable of carrying genetic information and reproducing themselves. This is also a question that still challenges science, but many researchers are exploring new ideas that may explain the great leap from an essentially chemical world to a biological one.

Genetic information flux. Font

One of the first steps of this great leap is to understand how a nucleic acid molecule has the essential role of storing information that can be transmitted to subsequent generations. One of the most accepted hypotheses for the origin of genetic information is that of the RNA world, which suggests that RNA arose before the DNA molecule. However, in living organisms today, the flow of genetic information begins with DNA. Why then, would the first cells or proto-cells have RNA as the main source of genetic information?
DNA in today's cells require a complex machinery of proteins to be replicated. These proteins, in turn, require a DNA molecule that carries the information for later translation. Thus, the dichotomy of which originated first, DNA or protein, makes this question virtually unsolvable.

RNA world hypothesis. Font
For this reason, many scientists suggest that RNA was the first informational molecule to emerge, as it contains two essential properties for the maintenance of a primitive cell: a ribozyme activity, which makes it capable of catalyzing its own replication, and a catalytic activity capable of synthesizing some proteins. We still do not understand how mutations in the RNA molecule gave rise to DNA or how DNA was subsequently selected as the main source of genetic information of the cells.

Another important step for the formation of the first living cells is the emergence of compartmentalization. All cells have a plasma membrane composed essentially of phospholipids that guarantees the protection of the cytoplasmic content. Compartmentalization stores the molecules inside the membrane, facilitating chemical interactions. In addition, the selective permeability of the plasmatic membrane makes the chemical concentration inside of the cell different from the concentration of the surrounding environment, a characteristic fundamental for many cellular processes.
Lipid compartments are spontaneously formed due to their amphipathic nature - just mix a little oil into a glass with water and soap and watch. On primitive Earth, the compartments likely formed around biomolecules and some constituents that eventually gave rise to the first forms of metabolism and cellular functioning.

You can access Part I here!

Wednesday, May 9, 2018

Ocean research is the key to a sustainable future

Illustration by: Joana Ho

Did you know that the UN declared next decade (2021-2030) as the decade of ocean science?

The ocean covers 71% of the Earth's surface. It helps to regulate the climate and provides a number of essential and, in some cases, untouchable resources for man. The ocean is a source of food, raw materials, energy, and transportation, in addition to being used for recreation and leisure.

Currently, more than 40% of the global population lives in regions within 200 km of the sea. In addition, 12 out of 15 megalopolises are coastal.

However, rapid industrial development and population growth have deeply impacted the oceans. Climate change, unsustainable exploitation of natural resources, pollution, and habitat degradation threaten the productivity and health of our waters.

Storms, proliferation of toxic algae, and coastal erosion are just a few of the consequences of this, which are devastating to communities living in coastal regions. Throughout human evolution, we have devised strategies to increase our resilience to such sea damage. But for how long will that be enough?

In 2015, the southwest coast of Brazil recorded winds of 106 km/h – a light hurricane typically has speeds of about 115km/h – so it was almost there. From these winds, the area suffered much damage including fallen trees and billboards as well as the destruction of some buildings.

In 2017, a windstorm left 38,000 homes without electricity and knocked down more trees and commercial signs. In the Port of Santos (SP), the largest in Latin America, a man was trapped in a crane.

This all happened because the sea water was warmer than normal, generating areas of low pressure and creating instabilities that allowed for the development of these strong winds.

And that's not all. Let's think about food:

Research shows that more than 50% of the fish species consumed for food in the world are being exploited above the sustainable limit. According to a 2006 study, led by Boris Worm of the University of Halifax in Canada, fish and seafood stocks are expected to collapse by 2048 if nothing is done to contain the loss of marine biodiversity.

Brazilian sardines (Sardinella brasiliensis), for example, are widespread throughout Brazilian cuisine. It is an extremely important species for the Southern and Southeastern regions of Brazil. Rich in various nutrients, it has always been considered a low-cost and nutritious food.

However, due to overfishing, its price has been rising over the years. Sardine stocks have already collapsed twice, once in 1990 and again in 2000. In addition, sardines are a species that suffers directly from the influence of environmental variation. By 2016, the amount of fished sardines was once again reduced to frightening levels. Some experts even characterized the episode as yet another collapse of the species.

This shortage was caused by abnormal water warming, a process that is associated with both the El Niño phenomenon, which occurred that year, and global climate change. It is worth mentioning that the region is also under political instability, with constant government turnovers and a reduction in ocean investments, which does not help the scenario at all.

Now imagine if phenomena like El Niño became more frequent and more intense with climate change? How long will the species last?

We need to find new ways to use natural resources and use them conscientiously. However, according to estimates by the UNESCO Intergovernmental Oceanographic Commission (IOC), the average national expenditure on oceanographic surveys varies from 0.04 to 4% of the total invested in research and development. This tiny budget is too little to achieve high-quality studies that involve long-term processes. Oceanographic research is quite expensive, because it requires ships, on-board laboratories, equipment, qualified personnel, et cetera.

But there is still time to reverse this situation.

Scientists and activists have gradually organized a social movement that led the United Nations, at its General Assembly in December 2017, to declare the next decade as the Decade of Ocean Science for Sustainable Development.

The initiative aims to encourage further action for a more integrated and sustainable ocean observing system, in order to facilitate making new discoveries by monitoring the coast and deeper waters, thus broadening research to promote ocean conservation and natural resource management. Activities for this period will be the responsibility of UNESCO's Intergovernmental Oceanographic Commission (IOC).

The process was long and hard fought. The 2012 Rio + 20 final document named "The Future We Want" made extensive references to the ocean. In 2013, the Global Ocean Commission was created, and in 2016, released its report about ocean degradation and the need for more effective policies to help restore the health and productivity of these waters. The 2030 agenda for sustainable development, launched by the UN in 2016, also highlighted the oceans as protagonists for conservation actions.

This UN statement is a glimmer of hope for a more sustainable future, but it calls for greater engagement of researchers, politicians, government, and the general public. More research, incentives, and respect are essential if we seek to advance our knowledge about the waters around us; we must make better use of available resources to ensure their existence for future generations.

It is vital to find solutions that allow us to understand the changes that are taking place and to reverse the damage before it is too late.

The UN initiative aims to transform the way global society views and uses the ocean. As suggested by goal 14 of the Sustainable Development Goals (SDG), it will coordinate its actions to foster the conservation and sustainable use of the ocean, seas, and marine resources.

Before progress can be made, it is essential to understand the lack of knowledge that we still have when it comes to the blue immensity:
  • There is no internationally accepted methodology for estimating the economic value of services provided by the ocean to the human race
  • Science is not yet able to assess the cumulative impacts of climate change, marine pollution, or anthropogenic activities on ocean health
  • Only 5% of the ocean floor has thus far been mapped
  • Over 250 million km2 of the ocean floor is in complete darkness, yet it shelters possibly millions of still unknown species
  • Only 3 people have ever explored the deepest point of the ocean

The next decade will be our time to support, demand, and celebrate new achievements for the health of our ocean, so that we can make the services and resources of the ocean available to future generations.


Global Ocean Commission. The Future of Our Ocean: Next steps and priorities Report. Available at (Global Ocean Commission, 2016).
Ministry of the Environment. Management Plan for the sustainable use of Sardines-Verdadeira in Brazil. Source:Ibama:

UNESCO. United Nations Decade of Ocean Science for Sustainable Development (2021-2030) UNESCO press release. Available at: (2017).

United Nations General Assembly. The future we want. Rio+20 conference outcome document A/RES/66/288. Available at:

Friday, April 13, 2018

Big Bang to the Dawn of Life: A Brief History

By Amanda Bendia

English edit: Katyanne M. Shoemaker

Part I - Big Bang: the origin of atoms and explosion of stars
Fourteen billion years ago: from the singularity
 to the greatest explosion of all time, the Big Bang.
smithsonian-institution/ what-astronomers-are-still-
It is estimated that the number of species that inhabit the Earth currently exceeds 8.7 million.  Not included in this calculation are the bacteria and archaea, which are microscopic prokaryotes. These microscopic organisms are single celled and devoid of a nucleus and membrane-bound organelles. The number of species of these prokaryotic microorganisms, surprisingly, surpasses the estimated 8.7 million eukaryotic inhabitants of the planet  (eukaryotes have a more complex cellular structure with nuclei and membrane-bound organelles and encompass all animals, plants, fungi, protozoa, etc.). Such immense values make us reflect on how such incredible diversity may have arisen throughout the history of our planet and the Universe.
To begin to discuss this question, we need to go back 15 billion years ago, to a point where everything we now know was concentrated in one single point. Can you imagine this? All of the humans and all other organisms that have inhabited the Earth, all of the objects we have produce with our technology, all of the molecules that make up our planet, all of the atoms of the billions of stars that we have already detected in the Universe, all of the Cosmos, gathered in this singularity. And then, there was the biggest “explosion” of all time: the Big Bang.
The origin of our solar system:
the ingredients for the origin of life in a

 cloud of stellar dust.

The Universe expanded, cooled and darkened. The first atoms formed and their accumulation generated large clouds of cosmic dust that would give rise to the galaxies. Within the galaxies, the first generation of stars formed; within them, atoms fused, first of hydrogen, but then giving rise to heavier chemical elements. When the fuel was depleted, the stars exploded and released these elements, enriching the stellar gases.
A new generation of stars began recycling these elements, and even heavier atoms were formed. The accumulation of clouds filled with cosmic dust - the nebulae - gave rise to planetary systems, including our solar system. During the formation of planet Earth, approximately 4.5 billion years ago, organic molecules composed of carbon formed and created all of the ingredients essential for the development of life.

Wednesday, March 14, 2018

Water on Mars and the deep ocean

By Jana M. del Favero

English edit: Katyanne M. Shoemaker

   At the end of September of 2015, NASA scientists publically confirmed the existence of liquid water on Mars, the Red Planet ( I remember when this news was released and how it caused certain uproar over the possibility of finding life there.

Landscape of the mysterious Red Planet; from the movie The Martian (

   We know that life depends on water: it is the largest constituent of every living being (e.g. the human body is composed, on average, of 60% water), it is necessary for photosynthesis, and it is indispensable for several other vital functions. However, the phrase just quoted neglects an important detail: life, AS WE KNOW IT, depends on water.

   This made me remember the following cartoon, about two giant tubeworms talking to each other:

   I had posted this cartoon on my personal Facebook page previously, but then I reflected: how many of my friends know what giant tubeworms are? Or what hydrothermal vents are?

   Tubeworms are marine invertebrates in the phylum Annelida (yes, the same as the earthworms) and the class Polychaeta (aquatic worms), but they are sessile, i.e. they live fixed on an underwater surface. Their body is rounded by a tube, which extends the length of the whole body. The one illustrated in the cartoon are of the species Riftia pachyptila, popularly known as the giant tubeworms. These worms can live several kilometers down in the ocean, and they can reach a length of 2.4 m with a diameter of 4 cm. (more information on:

   A hydrothermal vent is a fissure in a planet's surface from which geothermally heated fluid emerges. The water that penetrates the crust at deep depths reacts with the minerals present, undergoing physical and chemical changes along the way. Usually there is an “oasis” of life along the hydrothermal vents. This is due to chemosynthesis, a process in which microorganisms use chemical energy to produce organic matter from carbon dioxide.

   Prior to the discovery of hydrothermal vents in the 1970s, the scientific community assumed that all life in the ocean depended on photosynthetic production, mainly produced by phytoplankton. Since photosynthesis depends on sunlight, it was like saying that all of the life in the oceans depended solely on the sun! The hydrothermal vents and the abundance of organisms that live around them proved the opposite.

   And that's the point I wanted to get to in this post: WE KNOW AS LITTLE ABOUT THE OCEAN AS WE KNOW ABOUT SPACE!

   We have explored around 1% of the oceans, and they cover 80% of our planet.(,58d9a38790aea310VgnCLD200000bbcceb0aRCRD.html)Most of the ocean is only about 3 km deep, but Mars is about 60 million miles away from Earth! I am not saying that scientific exploration of space is not important, but I wish that the amount of money invested in space studies and the media attention space discoveries receive would also be given to the oceans. We know so little still, and yet they are so much more present in our lives.

Thursday, December 21, 2017

Two reasons to watch the documentary “Mission Blue”

Translated by Lídia Paes Leme

Edited by Katyanne M. Shoemaker

In our first post in the Women's session “Old challenges for current women” we received a suggestion by Prof. Otto Muller P. Oliveira to post about the documentary “Mission Blue.” Indeed this documentary deserves a special mention in our blog because, aside from the excellent production, its content is simply inspiring.
The documentary “Mission Blue” was released in 2014 and tells the story of the incredible biologist Sylvia Alice Earle, explorer, author, mother, grandmother (amongst a thousand other possible titles) and her campaign to create a global coalition of marine protected areas, called “Hope Spots.”

When watching the movie, it is impossible not to fall in love with and be inspired by two “characters.” The first is the organization itself, also called Mission Blue (, which was created in response to the prize Sylvia Earle earned in 2009 at “TED PRIZE WISH” (watch the talk here). In that talk, Dr. Earle encourages the use of all possible media (movies, expeditions, internet, new submarines) in a campaign to inspire public awareness and support for a worldwide network of marine protected areas. If these “Hope Spots” are wide enough, it could be possible to save and restore the planet's blue heart! Today, Mission Blue is a coalition of over 100 groups, from multinational corporations to groups of scientists, concerned with matters of ocean conservation. Mission Blue's website brings an interesting but scary statistic: only 2% of the World’s ocean is protected, hence the importance of this kind of effort.


The second reason to fall in love with this film is the main character, Sylvia Earle, a woman that turned 80 in August 2015, who actively keeps studying, exploring, diving, and defending the ocean (learn more Sylvia completed high school at the age of 16, undergrad at 19 and her masters at 20. During her Doctorate, this rhythm slowed down, due to marriage and kids, but soon Sylvia returned to her frantic pace. In 1964, when her kids where only 2 and 4 she traveled for 6 weeks on an expedition in the Indian Ocean. According to Sylvia, she didn't know she'd be the only woman on board, for she was invited as the only botanist, not only woman. A reporter approached her in Mombassa, Kenya, from where the ship would depart, and Sylvia remembered being interested in talking about her work, but the reporter only wanted to know about what being on the ocean with so many men would be like. After all, the article was called “Sylvia sails away with 70 men, but she expects no problems.”
Despite everything appearing well, Sylvia implies in some interviews that her scientific expeditions may have lead to the end of her first marriage. This is a recurring difficulty faced in the scientific world; it is common to have campaigns where the scientists are away for weeks, sometimes months, without any communication with family. In 1966 Sylvia finished her Doctorate, and in 1968 she traveled 30m deep in the waters of the Bahamas in a submersible, 4 months pregnant with her 3rd child and in her second marriage.
In 1969 she signed up to participate in the project Tektite, where scientists lived weeks in a laboratory placed under the sea, at 15m depth. Despite her 1000+ hours of diving experience and her excellent written proposal, she was not allowed to live together with men underwater in Tektike I. The following year however, she was invited to lead the Tektite II project, with a women-only team. The success of this team was an important milestone for women in research, and it set a precedent for future aquatic and space expeditions to include women in their teams.

Picture: Bates Littlehales.

After her experience as a mermaid, Sylvia became a popular face in the media and her career took off (we'd say, all other qualities aside, she also has a lovely face). In 1979 Sylvia walked on the ocean floor at depths never before touched by any other human. This was done using what is called a JIM SUIT, and was used at a depth of almost 400m. This adventure resulted in the book “Exploring the Deep Frontier.”

Image: Dr. Sylvia Earle in Deep Rover Submarine. Font:

In the 80's, together with the engineer Graham Hawkes, she started a company to create submersible vehicles, like Deep Rover. This partnership ultimately led to her third marriage, one where the offspring were the submarines created by them. One of her daughters currently works with her in her company.

When asked if she had problems reconciling family and career, Sylvia says yes, many, and that she tried to rearrange her life, having a laboratory and a library at home. For women that dream about following a scientific career, Sylvia advises “Try, you'll never know how it would be if you don't try.”