Tag Archives: socioeconomic status

Wastewater analysis can reveal how wealthy, healthy, and well-fed you are

New research from the Queensland Alliance for Environmental Health Sciences in Australia is taking a very unusual approach to understanding the people in different communities: analyzing their sewage.

Image via Pixabay.

The team reports that varying income levels in different communities are linked to different food and drug consumption habits. While that conclusion itself isn’t exactly surprising, the way the team reached it is. This is the first study of its kind to show that these habits result in noticeable differences in the wastewater of individual groups of people.

Data dump

Preivous studies have shown that our drug consumption shows up in wastewater — but this is the first study to track other lifestyle traits using the same approach.

“Although [wastewater-based epidemiology] has primarily been used for measuring drug consumption, our results demonstrate that it can be used to identify sociodemographic patterns or disparities which associate with consumption of specific chemicals or food components,” writes the team, led by Phil Choi, a Ph.D. student at the Queensland Alliance for Environmental Health Sciences in Australia.

Wastewater from wealthier communities, where people had higher educational achievement, showed higher levels of vitamins, citrus, and fiber, the team reports. Wastewater from poorer communities, where people were overall less educated, showed higher levels of prescription pain relievers and antidepressant medications. Wastewater analysis can thus be used to gain insight into the consumption habits of individual communities, the paper concludes.

The study examined samples from 22 water treatment plants from six Australian states over seven consecutive days in 2016. The results were compared to 40 different socioeconomic factors from Australia’s national census (factors such as rent price and education level). Choi’s team then drew correlations between these factors and compounds found in the urine and feces of residents.

One of the strongest correlations the team identified was between socioeconomic status and prescription drug use. Wastewater treatments plants that serve areas associated with lower overall socioeconomic status had higher levels of several prescription drugs in their wastewater. These drugs are:

  • tramadol, an opioid pain reliever;
  • desvenlafaxine, an antidepressant;
  • mirtazapine, an antidepressant;
  • pregabalin, a prescription pain reliever;
  • atenolol, a blood pressure drug.

While people of lower socioeconomic status do report higher drug use than others, the team notes that the study shows their method is useful to analyze overall trends in a community.

Wealthier and healthier

Dietary fiber and citrus consumption were also strongly correlated with socioeconomic status — an indication that the wealthier households had an overall better diet. Wastewater from wealthier areas also had higher levels of proline betaine, a component of citrus flesh. Enterodiol and enterolactone, which are components found in the waste of people who eat plants, were also found in higher concentrations than in the wastewater of other areas, the team reports. These results suggest that people in wealthier communities mix more fresh fruit and vegetables in their diet.

Areas with higher overall rent rates — those over $470 a week — wastewater contained significantly higher levels of vitamins B3, E, and B6. The researchers identified these compounds by looking for their metabolites (what’s left after our bodies process a particular substance) in wastewater. Areas with the lowest rent rates — areas where people of lower socioeconomic status live — showed lower levels of these vitamins in their wastewater.

The study aims to showcase the role that wastewater-based epidemiology can play in efforts to monitor public health and illicit drug use. There is an ongoing debate on the merits of this field of research, the team notes, revolving particularly around the issue of privacy (the method can be used to gather data on people without their consent). For the moment, however, the findings confirm previous results on the relationship between socioeconomic status and health — richer people eat better and have fewer health issues, the team explains.

The paper “Social, demographic, and economic correlates of food and chemical consumption measured by wastewater-based epidemiology” has been published in the journal PNAS.

Growing up in poverty affects the structure of the brain — even in adult life

A new study has found that growing up in vulnerable socio-economic can affect a child’s brain — and the impact carries on well into adult life.

These images of the left and right hemispheres of a 55-year-old’s brain depict varying thickness in the cortical grey matter, where red is the thinnest and yellow is the thickest. University of Texas at Dallas researchers are studying how the socioeconomic status of adults is related to the function and anatomy of the brain, including cortical thickness and brain network organization. Image credits: Gagan Wig.

We’ve known for quite a while that lacking adequate education, nutrition and access to healthcare, adversely affects a child’s brain — it’s a matter which has been studied extensively in the past. But now, a new study from researchers at University of Texas at Dallas examined an effect that is not so clear: how the adverse effect carries on into adulthood.

“We know that socioeconomic status [SES] influences the structure of the brain in childhood and older age, but there’s been a gap in the research. We wanted to see if there were relationships between SES and the brain across a wider range of adulthood,” said Dr. Gagan Wig, assistant professor in the School of Behavioral and Brain Sciences at UT Dallas and corresponding author of the study published online in the Proceedings of the National Academy of Sciences.

[panel style=”panel-warning” title=”Socioeconomic status and the brain” footer=””]Children’s cognitive abilities and school achievements are deeply affected by socioeconomic status. Numerous studies have reported lower cognitive performance in relation to unfavorable environments.

The evidence suggests that human brain development occurs within a socioeconomic context and as a result, childhood socioeconomic status influences neural development — particularly of the systems that subserve language and executive function. Simply put, poverty can be bad for children’s brains.[/panel]

The study included 304 individuals ranging between 20 and 89 years of age. Their socioeconomic status was assessed both objectively and subjectively, based on the participants’ own beliefs. Then, their brain activity was assessed through magnetic resonance studies, during a state of resting wakefulness. Researchers also used anatomical brain scans to measure the thickness of cortical grey matter in each individual’s brain.

The team reports that in middle-aged adults (ages 35 to 64), a lower socioeconomic status was associated with a more disorganized brain network and thinner cortical grey matter. The relationship persisted even after researchers corrected for demographics, measures of both physical and mental health, and cognitive ability.

It’s not clear how this effect manifests, Wig told ZME Science, but we can likely expect a number of downsides for people growing up in disadvantaged socioeconomic environments.

“Other studies, including our previous work, have demonstrated that the brain variables we examined (measures of brain network organization and cortical thickness) are correlated with cognitive ability across a number of domains (e.g., fluid intelligence, long-term memory). Given that this relationship exists, we controlled for individual differences in cognitive abilities in our analyses. One prediction though, is that individuals who have less organized networks and thinner cortical grey matter may exhibit faster cognitive decline as they age and/or be particularly susceptible to age-related disease.”

While the correlation seemed to fade for the elderly, the fact that the brain effects carry on well into adulthood is a major point of concern. Even more worryingly, the correlation carried out well above the poverty line. The one point researchers stress is the fact that socioeconomic status is associated with numerous lifestyle changes, and it’s hard to pinpoint which one of these changes is the main culprit (or if there is a mixture).

“What we have found in middle-aged adults is a correlation between socioeconomic status and brain function and anatomy,” Wig said. “What makes these results more striking is that the individuals we studied were predominantly above the poverty line. This provides evidence that SES-brain relationships are not limited to individuals at the extreme ends of SES, but are present across a broader SES range. However, because differences in SES can be associated with differences in many factors, including those related to diet and health behaviors, access to health care, and levels of stress, it’s not yet clear which of these, if any, is the source of the observed relationships.”

The relationship appears to be linear, Wig told ZME Science — in other words, the lower your socioeconomic status, the more your brain is affected. However, it’s unclear if this carries out for the entire economic range.

“Yes, the observation was linear within the middle-age adults. As we note in the paper and in the press release, this study sample doesn’t have too many people falling below the poverty line, so it is presently uncertain whether any non-linear relationships are present between the brain variables and SES across a broader SES range,” Wig explained

However, regardless of what the decisive factor is, the bottom line is that socioeconomic status is such an important element for brain health, even in middle age. This is troubling and warrants further research.

Wig says it’s still too early to make policy recommendations, but he emphasizes the need for a better understanding of this phenomenon.

“This data demonstrate that an individual’s socio-economic environment continues to relate to their brain function and anatomy beyond childhood into middle-age adulthood, and that it’s important to study this age segment in order to gain a deeper understanding of brain health into older age. This is particularly important given the changing demographics of the population in many countries.”

The study has been published in Proceedings of the National Academy of Sciences.