Fringe Musings: Popular Science

19.2.16

Lead in Water: Why? Where? and What Can We Do?

By now we’ve all heard about the tragic water situation in Flint. To very briefly summarize, after a switch in water sources in Flint, Michigan, there was an increase in leaching of lead from old pipes in flint into the water, resulting in a massive exposure to dangerous levels of lead across the area. Unfortunately, for many of this a situation like this could hit closer to home than we realize, with many older homes containing lead in the pipe infrastructure that, depending on the situation, could/is leaching lead.

What’s the Problem with Lead?

Most of us (hopefully) know that lead is not good for us. According to the WHO, lead poisoning at its worst attacks the central nervous system and can, in extreme cases, be fatal. Even relatively low levels of lead exposure can cause adverse effects, particularly in young children, including complications in brain development that can lead to permanent intellectual and behavioural disadvantages. Even doses that were previously thought to be benign are now recognized as being biologically toxic by most regulatory bodies, leading to the ultimate cease in use of lead in various products such as paint, gasoline, and water pipes and fixtures. The unfortunate truth, however, is that the once pervasive use of lead has made it extremely difficult to eradicate existing lead-containing structures. The latest case of lead-related disasters that has caught media attention is the lead found commonly in pipe-fittings and solder connections for municipal water systems. While this inclusion of lead in and of itself is not necessarily problematic, (the leaching of these lead compounds into most water running through the pipes is low under ‘normal’ conditions) chemical and/or physical properties of local water supply can lead to increased lead leaching from old pipe fittings, leading to unsafe lead in drinking water as evidenced by the situation in Flint, Michigan and other cities across North America.

Why Did We Even Use Lead In The First Place?

Despite being biologically toxic, lead is/was actually pretty useful. Leaded-paint was widely used until the 1970s owing to its unique ability to decrease drying time, resist corrosion, and generally preserve appearance. Believe it or not, the use of lead in pipes is so historic that the term ‘plumbing’ was actually derived from the Latin word for lead - ‘plumbum’ (I personally can’t believe I never picked up on this). Lead was likely the material of choice for so long due to its easy-to-manipulate malleability combined with its long-lasting durability, making it a great long-term choice for large-scale water distribution systems. As was alluded to earlier, the use of lead in pipes is not necessarily detrimental, although certain water chemistries, namely presence of certain dissolved salt species and acidity/alkalinity, can increase leaching of lead from pipes, resulting in unsafe concentrations in tap water for some homes.

How Much Lead is Safe?

As with almost anything in chemistry, concentration matters. Despite the high toxicity of lead, we are all likely exposed to very low concentrations of lead, with no negative biological impact. In fact, test almost any municipal water sample and you’ll find that although the lead concentration is not identically zero, there is often little cause for concern. The most significant (and troublesome) source of exposure to lead through water is through the aforementioned water distribution infrastructure. According to Health Canada, the maximum concentration of lead deemed acceptable in drinking water is 0.01 mg/L, a concentration thought to be high enough to induce negative effects particularly in young children.

Unfortunately, there are places, even within Canada, where lead levels in drinking water from taps is higher than the national acceptable maximum due largely to the use of old lead in pipes and water fixtures installed pre-1950s.

So What Can We Do?

While the most attractive solution for everyone is to simply remove all lead-containing infrastructure from water service lines, this is a complicated feat. Many cities have put plans in place to replace lead pipes on city owned land; however, when it comes to private property, this responsibility falls into the hands of the homeowner; a task that is far too expensive for many. In light of this, municipalities have resorted to chemical addition tactics for reducing lead leaching from the existing pipes. These so-called ‘corrosion control plans’ vary by region and can range from phosphoric acid addition to the water supply thus producing a protective orthophosphate coating on pipe interiors, to pH increases by addition of NaOH known to decrease leaching ability. The choice of appropriate course of action (ideally) depends on inherent water properties in the region, as lead solubility is affected significantly by water softness and acidity.

Quite unfortunately, though not unexpectedly, this chemical addition has received backlash in some areas due primarily to lack of public knowledge about the chemical means of decreasing lead exposure. Public retaliation of this kind threatens to delay implementation of such measures, exposing thousands of people to dangerously toxic lead levels on a daily basis. Although I am certainly not one to believe in blindly trusting government officials, the fact is that years of science have gone into decreasing lead leaching, and what’s more, any addition of tiny quantities of (very safe) chemicals to your local water supply will most certainly be less harmful than the very real threat of lead poisoning. We can only hope that what we are currently witnessing in Flint will, if nothing else, help us to reconsider any reservations about current and upcoming chemical measures put in place designed to protect us, and motivate those that can to replace lead pipes.

References and Further Reading:

Health Canada: Minimizing Exposure to Lead

British Colombia: Resources Inventory Committee

City of Toronto: Drinking Water

5.2.16

Move Over Pluto: There's a New Planet 9 in Town

13.12.15

Overcoming Chemophobia-Phobia

29.11.15

What Does Your Music Preference Say About You?

Photo Credit: Hilary Clarcq

Could you go a day without listening to music? I’m talking nothing; no singing along to Taylor Swift in the car, no electronica at the gym, absolutely nothing. Realistically, probably not, if only because we encounter music unintentionally almost every time we leave the house. While we are all aware that music is a large part of life for many of us, perhaps it plays an even bigger role than we realize. We may even feel defined by our music preferences; seeing elements of the songs we listen to manifested in our attitudes, energy levels, and fashion choices. It turns out that not only are we influenced in some way by the music we listen to (or perhaps our personalities define the music we prefer), but also we actually use music preference as a social cue for assessing personalities of others. As a lover of both music and psychology, I am absolutely fascinated by the idea that our personalities and even neural pathways are measurably tied to music preference. As you may know if you are all caught up on your music psychology literature (…), there are various studies focused on making and understanding the correlations between music and the brain/mind. In one such example, researchers have found that music preference can reliably predict personality traits such as tendency towards extraversion or political leanings. What’s more, we are actually intrinsically aware of this link, and as such tend to use music to (correctly!) assess personality when meeting and getting to know new people. This link between brain and music can even be extended to neurological pathways that are selectively activated based on degree of preference for a certain song, leading to different brain responses for liked vs. disliked music that can be linked to the mind-wandering conscious experiences we have while listening to a particularly well-loved song.

What your Music Preference Says about You: The Link Between Music Taste and Personality

If you’re anything like me, you might find all types of personality quizzes oddly compelling (highly addictive, more like). Despite the fact that I am well aware of the traits that make up my personality (I mean, I’ve done so many quizzes at this point…), I am still a sucker for any online quiz promising to reveal my innermost workings at the click of a button. As it turns out, I’d probably be better off leaving the Buzzfeed quizzes behind and scrolling through the music saved on my iPhone. Researchers at the University of Texas have proposed and showed a statistically significant correlation between music preference and personality traits. Rentfrow and Gosling published results of several studies in 2003, whereby they asked groups of participants about music preference and compared these choices to various personality traits and self-reported attributes such as athleticism or intelligence. The results of their work were rather compelling, revealing a link between a subject’s choice in music and his/her personality traits, self-views and cognitive abilities. With music genres grouped according to an earlier study, the broad music categories of Reflective and Complex (encompassing the genres classical, jazz, blues, and folk), Intense and Rebellious (alternative, rock, and heavy metal), Upbeat and Conventional (country, pop, religious, soundtracks) and Energetic and Rhythmic (rap/hip-hop, soul/funk, and electronica/dance) were compared to traits including extraversion, agreeableness, emotional stability, openness, political views, athleticism, and intelligence. For example, if you’re a major fan of blues, you are likely to be an introvert who is inventive, open to new experiences, has high emotional stability, and is politically liberal. Conversely, hip-hop lovers tend to be high-energy extroverts who are athletic, agreeable, and see themselves as physically attractive. For simplicity, I’ve outlined some of the results in the graphic below:

In a related study, the same researchers were interested in how we might use this information in everyday life. For instance, do we inherently use music preference as a social cue for personality determination? It turns out that it is not only the case that people DO infer traits based on reported music preference, but we actively seek out the music taste of someone we might want to get to know. Researchers observed that when strangers were left to their own devices, music was the most talked-about subject in almost all instances. Basically, not only is music preference a reliable measure of personality, but also we somewhat unknowingly use it as such when getting to know others! This is great news for me, as it means I can choose whether or not I’d like to get to know someone without actually having to go to all the trouble of actually talking to them…(assuming I can gain access to their iPod).

Your Brain on Music: How Music Preference Affects Brain Response

Ok, so as we might expect, music preference is indeed closely related to a number of personal attributes and we seem to have the ability to learn which music preferences relate to which attributes and, what’s more, actively use this as a way to get to know someone. This does not, however, tell us explicitly why we might prefer one genre of music over the other (although in the study discussed above the researchers do propose some theories) nor does it tell us how our brains react to listening to different genres of music. Last year, the research team of Wilkins et al. sought to understand the effect of listening to a certain music genre on brain activity and also relate brain connectivity patterns to reported self-referential thoughts and memories experienced while listening to music.

Interestingly, the results of functional magnetic resonance imaging (fMRI) studies indicated that genre actually had little effect on functional connectivity, and it was instead the degree of preference for music that seemed to dictate differences in brain response. Moreover, when listening to preferred music, networks corresponding to brain functions related to self-awareness, self-referential thoughts and empathy were selectively activated compared to non-preferred music listening. These patterns were observed regardless of the genre of music and whether or not lyrics were present. The authors go on to hypothesize that the activation of this neural network could be responsible for the anecdotal feelings of introspection that we feel when listening to a favourite song or genre, and could explain why we selectively have these mind-wandering feelings when listening to music that we actually enjoy. Evidently, these findings have major implications for neurorehabilitation, and could even be helpful in music treatment of anxiety and depression through the use of preferred vs. non-preferred music.

As it turns out, music is much more to us than just a pastime. It plays a major role in our social interactions, as well as activates important neural pathways that lead to therapeutic experiences. So, could you go a day without listening to music? No! Why would you? It’s too important!

Oh, and for those of you wondering, my music taste lies somewhere between folk and rock. So there you go, I guess we’re not strangers anymore.

What is your favourite genre of music? Do the personality traits typically associated with your preferred music style apply to you?

References:

Rentfrow, P.J., & Gosling, S.D. (2003). The Do Re Mi’s of Everyday Life: The Structure and Personality Correlates of Music Preferences. Journal of Personality and Social Psychology. 84, 1236-1256

Rentfrow, P.J., & Gosling, S.D. (2006). Message in a Ballad: The Role of Music Preferences in Interpersonal Perception. Psychological Science. 17, 236-242

Wilkins, R.W., Hodges, D.A., Laurienti, P.J., Steen, M., & Burdette, J.H. (2014). Network Science and the Effects of Music Preference. Scientific Reports. 4, 6130

And this gem for all the ‘selfie’-lovers out there:

Qui, L., Lu, J., Yang, S., Qu, W., & Zhu, T. (2015). What does your selfie say about you? Computers in Human Behavior. 52, 443-449