Environmental Epidemiology - Science topic

Public health positions are available at various levels of government health agencies, military bases, and university public health schools. They are involved with environmental compliance in various manufacturing companies and industries. And those with experience are in demand by environmental law firms as expert consultants in legal cases.

Dear Dr.Hasan Bin Sohail: Heatwaves lead to direct effect like hyperthermia and can be avoided by cold water locally or systemically(drinking).while the indirect effect on respiratory system (air passages)and can be avoieded by ventilations.

Generally vit.C and cold drinking important aid to stop heatwaves.Thanks

Hi Hasan,

Was there a particular reason you specified your temperature effect as a linear one, i.e. " argvar=list(fun="lin")"? Usually investigators would attempt to explore the non-linear relationship in the DLNM framework by specifying a natural cubic spline (see the references provided by Anwar above). I think how you specified the postulated relationship could have influenced your results. Perhaps you can explore the non-linear relationship instead?

This is an alternative calculation. You can put the value and check. For example, for one unit decrease in x is associated with exp(-2.5-0.14*1) / exp(-2.5-0.14*2) = 1.15 times risk of hospital admission on average.

1. Clear and effective oral and written communications skills focused on translating science into policy and programming-relevant insights. 2. Management skills (people, projects, finances, deliverables) - without these you'll find it hard to secure the funding to continue research. 3. Humility - build on what you know, but accept that there is so much that you don't know. 4. Dedication to the cause of rigorous and honest science in whatever kind of research job or career you pursue after graduation. 5. Commitment to mentoring peers and the subsequent generation - you know a lot that few others do so share it.

Would you like to cite the variables of your study more clearly? Are there two or three variables? In the case of quantitative variables, it could more simply be a problem of correlation between two variables or between two variables taking into account a third one.

Otherwise, the types of interaction encountered in medical

research may be a multiplicative interaction

or an additive interaction.

Multiplicative interaction is measured by relative risk or

odds ratio. The observed effect may be a multiplicative

synergy or a multiplicative antagonism.

Additive interaction is measured by the difference in risk.

the observed effect may be additive synergy or additive antagonism

I would imagine that is because social environments have been primarily explored using qualitative methods, and that sort of evidence is still not palatable in the science field.

I would just add two more comments to Jochen's answer:

1. You can run some diagnostics using gam.check(model1) and also plot the model with plot(model1). The latter will give you a visual that may help you interpret the relationship between temp and cvd. However, I notice that the deviance explained is 1.68% (see the second to last line in the summary output); since this is so low, the relationship between these two variables may be very weak, or there may be some other issues with the model (the diagnostics can give insights here).

2. You ask "what these parametric coefficients ... mean?" I will just reiterate that GAMs are different from GLMs in that there are no linear coefficients (betas) to interpret.

please check Z library for more references

please check Z library for more refrences

Tee: In 1928, in the Cutter Lecture at Harvard, Wade Hampton Frost introduced the epidemic triad. The lecture was published in AJE in 1976.

Dear Dr. Peplonska

Radiation associated with breast imaging is a sensitive issue, particularly for women who undergo mammography as a screening measure to detect breast cancer. Misinformation and misunderstanding regarding the risks associated with ionizing radiation have created heightened public concern and fear, which may result in avoidance of diagnostic procedures.

I think following links could be helpful for your research:

Regards,

Ata

Prof. Andrea Baccarelli (Harvard University) and Prof. Valentina Bollati (Milan University) study this matter.

Hi Pablo

This paper may help you to find a good answer to your question.

J.C Fensterstock et al., " The Development and Utilization of an Air Quality Index," Paper No. 69-73, presented at the 62nd Annual Meeting of the Air Pollution Control Administration, June 1969.

And another one. Please download attached file

In the US there are air quality monitoring stations that produce data for an Air Quality Index Report having to do with particulate matter from: ground-level ozone, particle pollution (also known as particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide. When the air quality is poor the local news will release air quality warnings to the areas affected and their risk. 

Here are two links on that system:

Pollen is monitored in a few ways.  The National Allergy Bureau™ (NAB™) is the section of the AAAAI’s Aeroallergen Network responsible for reporting current pollen and mold spore levels.

Pollen counts tend to also be collected on a state by state or locality basis.  Here is an example from North Carolina: http://daq.state.nc.us/monitor/pollen/.  I am unsure if these groups report into the NAB or not.

Our local news stations are very good about publicizing this information when risks are high related to air quality for people with respiratory health issues.  Based on this information, many schools and child care providers cease outdoor play until the air quality measures are back in a safe zone.

Hope this helps.

Both are distinct with regard to their probability of likelyhood: as its name indicates, an "upper bound" estimate (UBE) is a "higher" value that is still consider reasonable with regard to its probability of occuring (e.g. 90 or 95th percentile value), whereas a most likelyhood estimate is the most probable overall, thus not the most probable "high" value like the UBE. With limited number of data, the MLE is a safer bet as to its representativeness of the available data, since upper bound values are often more uncertain when considering the tails of a probabilistic distributions of values; often, you need more data to be able to determine a likely robust UBE in any given distribution. However, from a risk assessment perspective, UBE are considered more conservative, therefore they may be chosen even if the may be more uncertain. Thus, your choice will depend of your objective: being more "safe" or being more "likely representative". 

We once contemplated a study of the salience of public health issues (in our case stress related) that were loaded up and viewed on u-tube. This can be monitored if you have a good tech person. Another metric to think about Tee.

Thanks. Your tip for establishing a base station and post-processing is a good one. I'll do that.

for an insightful framing of the scientific questions, look at The Natural Step's "system conditions" for sustainability. The Natural Step seems to be somewhat out of fashion among Americans working in this area, but the framework is immensely valuable conceptually.

The most obvious study on improvement is: "Effect of air-pollution control on death rates in Dublin, Ireland: an intervention study" by Luke Clancy, Pat Goodman, Hamish Sinclair, Douglas W Dockery, Lancet 2002; 360: 1210–14.

Whether risk is associated with chemical or physical characteristics is a good question and it seems that jury is still out.

How far have you gone and what angle are you aiming at. A variety of studies have been carried out on this topic. I don't understand what you mean by specified policy/ guidelines. Is it that your country do not regulate minimum standard for housing because these are the fundamentals. Several aspects of housing relate to health like mental health can be associated to housing density, design, environment etc; domestic accidents and housing design; the sick building syndrome is another aspect. There are several ways to look at it. Please visit the world Health Organization (WHO) site. My Masters thesis is titled: An assessment of the impact of housing quality on health. I actually had to compare two different housing locations one with standard housing and the other with substandard housing relating it to common ailments like malaria. I correlated the cost of health with cost of housing using environmental valuation methods.So please be more explicit may be I can be of help. cheers!

As a new user of RG I'm very interested in this conversation. I noticed that RG is somehow "different" than other professional social media and I really appreciated the "open discussion" philosophy. I agree that an "open bulletin" space could generate some interesting brainstorming and possible collaborations. Unfortunately nowadays with tigher project budgets traveling to more than one conference a year is increasingly more difficult. Virtual venues could be the answer.

Thanks Dr. Guidotti for the interested EOH articles uploaded.

Because of the uncertainty inherent in the current practice of risk assessment (NAS and U.S. EPA paradigm), and the limited nature of epidemiological studies (limited in the number of people sampled/responding), it is often the case that the two are not directly comparable. For example, risk assessment may identify an unacceptable cancer risk in an exposed population after a hypothetical chemical release. Such risk assessments typically use default/generic exposure parameters and U.S. EPA defined toxicity values, which may include an aggregate of uncertainty factors that range from 10 to 1,000,000. The result of risk characterization might be a cancer risk of 5E-05 (5 times the acceptable target risk of one-in-a-million or 1E-05). In contrast, a large epidemiological study of the hypothetically exposed population is unlikely to sample (get meaningful responses from) more than 10,000 persons, and consequently does not have sufficient power to validate the result of the risk characterization. In such cases, the risk characterization should be considered a tool for evaluating the potential health risk to the population with a clear understanding of the uncertainty inherent in its calculation. Where epidemiology can demonstrate an increase in the observed frequency of disease or effect AND risk assessment demonstrates increased risk of that disease or effect, is suggestive of a causal linkage.

Hysplit model it's free and requires internet

Dear Tony, The hydroxyapatite which comprises to be the principle component of bone and which has biologically evolved to be flexible by nature turns to fluorapatite which is brittle and prone to bending exposure to excessive fluoride ove a period of time.

Fluoride also has a differential affect on our skeletal system. It increases the bone density in axial skeletal system like skull and spine but reduces the bone strength of appendicular skelatal system like hands uptill shoulder blades and legs uptil the pelvic gurdles. Hence vertebra fractures is aided by presence of fluoride but hads and legs become brittle in the presence of excess fluoride!

Dear Tony, You can use a whatman filter paper to get rid of silt and other visible impurities. If that does not help then use a .22 micron filter paper for filtration using a syringe filter. I hope you are using Fluoride ion selective electrode for your analysis because that is faster and more accurate than even ion chromatograph, though IC is good enough if you are doing a comprehensive ion analysis of anions. Phosphate ion is know to have an interference in fluoirde ion detection.

Thanks for reply

i read in essential of geology medical a chapter dealing fluoride so the concentration of fluoride depend of the geology nature of this region for ex a region with a high concentration of calcuim you will be assist with a low concentraion of fluoride in drinking water ,in granite rock