.awk

func ltrim(s) { sub(/^[ \t\r\n]+/, "", s); return s }
func rtrim(s) { sub(/[ \t\r\n]+$/, "", s); return s }
func trim(s) { return rtrim(ltrim(s)) }

BEGIN {
    factors["s"] = 1
    factors["m"] = 60
    factors["h"] = 3600
    factors["d"] = 86400
    factors["y"] = 31536000

    for (factor in factors) {
        factors["Y" factor] = 1000000000000000000000000 * factors[factor]
        factors["Z" factor] = 1000000000000000000000 * factors[factor]
        factors["E" factor] = 1000000000000000000 * factors[factor]
        factors["P" factor] = 1000000000000000 * factors[factor]
        factors["T" factor] = 1000000000000 * factors[factor]
        factors["G" factor] = 1000000000 * factors[factor]
        factors["M" factor] = 1000000 * factors[factor]
        factors["k" factor] = 1000 * factors[factor]
        factors["m" factor] = 0.001 * factors[factor]
        factors["u" factor] = 0.000001 * factors[factor]
        factors["n" factor] = 0.000000001 * factors[factor]
        factors["p" factor] = 0.000000000001 * factors[factor]
        factors["a" factor] = 0.000000000000000001 * factors[factor]
        factors["z" factor] = 0.000000000000000000001 * factors[factor]
        factors["y" factor] = 0.000000000000000000000001 * factors[factor]
    }
}

NR == 1 { next }

{
    isotope = trim(substr($0, 12, 5))
    halflife = trim(substr($0, 62, 7))
    halflife_unit = trim(substr($0, 70, 2))
    if (halflife ~ /^[0-9]+(\.[0-9]+)?$/) {
        printf "%s\t%f\n", isotope, factors[halflife_unit] * halflife
    }
}